If you spent 12k footballs with the ultimate coach and *didn't* get it it's because you picked the wrong players. In general the lower cost players are better - especially with coach bonuses. And the "gold" = longest ones are catastrophically bad. (Silver players may not have been ideal (the cheapest ones, especially the one that costs 41 are the best buy) - but probably would've been good enough)
In addition to my main city where I used the Ultimate Coach, I have four GE diamond farm towns. In all of them I saved up my footballs and only used them when the Epic Kit was a DS. On those days I used the Specials Coach and always chose the lowest cost/yard player. I played each town daily collecting all incidents along the way and completed all of the quests. At the end of the event my total yardage in all four towns was between 970 and 990 and they ended up in the Amateur League. I did not get the complete event building but that was by choice - I was not surprised. I did, however, get over 22 DSs in every city. Had I chosen the Progress Coach, the extra yard per play would have been sufficient to get me to 1200 yards in all cities. I'll agree that this event had much less wiggle room than earlier events but getting the complete building, without spending diamonds, was not impossible provided players collected incidents daily and made good choices regarding coaches and players.
4 out of 4 is statistically significant, and others here have had similar results.
How many of these players were doing the math to select the best player each and every play? I find myself wondering if this may be the largest difference.
Uber's post went right over your head huh?
You may not have noticed, but for most players it has already migrated there. I did all the quests. I collected all the Incidents. I used either the League or Progress coach each time I used Footballs. I did not choose players based on their prizes. I rarely chose the highest cost player. Did I read and follow the exact formula put forth by players from Beta? No. Nor should I have to. Diligently and intelligently working the event should be enough in a F2P game. Yet I fell short in 4 out of 5 cities. And two of them weren't even close. And I actually spent Diamonds in 3 of them. When actively and diligently working an event, I have never failed to get one fully upgraded main building in almost 8 years of playing. I can guarantee that I won't be spending money in the future with Inno taking this path. That chart you showed might just start taking a downward turn. It got that high from providing a great product, not from squeezing the players. I spent money when it was a great product. No more.
The bolded is the issue. It's just like avoiding being sniped and all the other myriad little calculations that a player has to use to be successful in this game. If you don't choose the right player every single play, you are not going to maximize the progress towards your goal (whether that be daily prizes or the main event building).
Likewise, the bolded is the issue. You shouldn't need prior knowledge from Beta, and you shouldn't have absolutely no room for error. You apparently disagree. That's fine, you're entitled to your opinion. It's just not shared by the average player. In fact, it's not even shared by all the experienced players. Most of us believe that if you play the event intelligently and diligently and collect all the event currency you possibly can, there should be a little wiggle room. Now there isn't, and it's a shame that such a great game has sunk to this level. It is most certainly not a great game anymore. It's still a good game, but a merely good game isn't worth spending money on. That's my bottom line.
With the +1 coach, the "cheapest is best" was accurate (there was one "individually more efficient" player that was a little more expensive ; but not enough so to be "worth it"). Without the +1 coach it's not always true (i.e. if you're using the league coach some of the time), but also not sufficient on its own to hit the 1040 yards without some luck.
From a practical perspective though, I don't expect many to take that approach even next year (if next year's balancing is the same), so it should be an option for those who have bad luck and notice before it's too late that they won't hit 1200. Me, I'm a chronic procrastinator who will do most of the event in the last 3 days usually 
Most likely you had good luck on incidents, hitting 1200 yards, and making the league cutoff (which was usually also around 1200), and got the (unpredictable) bonus upgrade for playing early. (You needed 1 of the 3 between 1200 yards, bronze league, or lucky beneficiary of midevent balancing). Thing is that bad luck on incidents would've cost you two of them (not hitting 1200 would also have cost you the league unless you adapted strategy) - and not everyone rushes into spending their event currency the first day - especially when they don't know there's going to be an incentive to do so.
When you add 1 and 1 and come up with 3. Never in past events has anyone needed that much good luck with incidents to complete a building. So obviously this event ISN'T the same as previous events.
I think that you had good luck in the past and credited it to either skill or INNO's generosity. This year you had bad luck or made poor choices and blame it on INNO. In my main city I used the Ultimate Coach and chose the most cost-effective players (same as the previous two years) and ended up with a complete building plus an extra level (same as the previous two years). In my diamond mines I used the Specials Coach and chose the most cost-effective players (same as the previous two years) and ended up short one level on the building in exchange for a LOT of daily specials (same as the previous two years). I don't see any difference in the mechanics between 2023 and 2022/2021. I'm not being "tone deaf", merely stating facts. Getting the complete building was near-certain thru following the previously mentioned strategy and collecting about 800 footballs from incidents. In each of my 5 cities I collected over 1000.
The trouble with you trying to say it's the same as previous years is in the sentence I bolded. And the reason it's not the same as previous years is that they more than tripled the price of the Ultimate Coach. I notice that of the three parts of that sentence, even you couldn't honestly say that using the Ultimate Coach is "same as the previous two years." So no, the difference between the past events and this one is not "bad luck or poor choices", it's that getting the main event building fully upgraded has been made harder and more expensive. And all of you apologists denying it won't change that fact.
I'm not denying it. I am stating unequivocally that I got the full building in each of my four cities without spending a single diamond, nor a single penny. Does it require some thought and planning? Yes. Is it impossible to do without diamonds? Absolutely not,.