I've made games on and off for several years with literally only one ever seeing the light of day. Each one was equally addicting and frustrating to make. I think all of us indie devs have ran into scopitis at least once or twice. Programming languages for whatever reason just don't click with me the way they used to, so struggling through Godot now makes me want to cry on the inside lol. RPG Maker, ironically, taught me more about programming and problem solving than Gamemaker did when I used it. But the biggest lessons I learned is
1) Make a prototype first with a core gameplay loop that is actually fun and functional.
2) Put effort into the game design document, but don't go overboard.
3) (Took me literally 13 years to learn), finish the effing the game.
That said, I have very little experience with game development overall in sprite of dabbling on and off for so long.