Let's see if I can tell some things correctly: You have visual and audio resources outside of Unity as well. GDevelop has its own asset download center, with RPG Maker you have all the plugins/scripts and with Godot you have templates for a lot of things. Maybe they don't have the same community as Unity, but between veteran forums and active discord servers there's someone who has written tutorials or fixes, or people that you can talk about the engine.
... Wa,waht, what? 200.000$? In my opinion, at that point you aren't a novice if you get that by game sells. 200.000$ by sells of a indie game means to me that you are doing very well, more than the majority of the people who uses itch.io, or even Itch.io itself. (This is not an insult to Itch.io or its users. I would be insulting myself).
I don't know how to put in precise words, but, do wathever you want, I'm not someone to tell you what to do in game engines but I don't recomend you call yourself a "Pro Unity" or defend the a-lot-of-money company who doesn't know you and if it could, it would make your experience more difficult with the service if it means making more money.
Regarding Godot, you don't lose anything by giving it a try, or Gdevelop, both engines are free and open source. Note that my main engine is a paid one and is closed source, but I admire Godot and Gdevelop, both the people behind those engines and their developers. And if I stopped using a software because it suffered a crash that caused it to lose data, I wouldn't be using a computer.