Perhaps you've simply played too long.
That ironically can be a players biggest drawback. The longer a player has to learn the game the harder it is for a player to.... well, learn the game. Reason being by the time a new feature is released a veteran player is already used to doing things a particular way. Whereas a new player will be learning it from scratch and be mastering any new mechanics.
You can be great at something and be one of the best in your field today, but here’s the thing. If you’re not continuously improving your game (not just FoE, all aspects of life) you’re always going to be surpassed by the new kid whose growth curve is higher because they’re improving while you’ve stopped improving. They’ve adapted while you’ve stagnated.
I don’t know how you (the OP) play, I don’t know what approach you take to FoE. I do know it’s the advanced Great Buildings (which you can get for free), how well you can arrange your layout, how well you know how to do events (funny how those that complain about events usually aren’t optimising their daily specials at all) and how well you manage all the other game mechanics that will determine how quickly you can grow.
All of this can be achieved for free. But you do need to put in the effort in the right areas or at the very least in learning (or relearning) how to improve. And here’s the funny thing, money doesn’t automatically change this. You can spend thousands and still be unable to compete with Free to Play players if those Free to Play understand the game better then you or are employing a better strategy.