I've been at lvl 40 for a long time now; the game is still a good motivator for me to take a walk or bike ride and catch some stuff.
While there have been a lot of improvements since 2016, the main things holding the game back are still a mediocre battle and gym system, even after the rework, and the lack of strategy due to how Niantic got rid of Sp. Attack and Sp. Defense by merging them, which left many Pokemon without a use. As it stands, you can just use 6 Mewtwo if you want, which is silly.
Could've been one of the best games of all time with original Pokemon stats and turn-based battle system, but alas.