At the end of the day, RPGM is just a glorified browser, sure it is easy to start out for a new developer, but once you start wanting to do more complex stuff, you quickly end up having to write 90%+ of the code in raw plugins anyway, which defeats the whole point by then of what RPGM offers, and with a language, that was never made for making games (and if a game gets big enough, the engine even becomes prone to crashing when saving the game, from the sheer size of the database json's (Also even with MV there is VERY limited searching functionality in the engine, VXAce I believe have NONE, so it is really tedious to navigate in a big game).
It really is a terrible engine in all aspects. Yes you can make amazing games with it, but to do so requires more effort, and probably with a lower performance result that most other game engines would. the ONLY good thing about it is the ease of use for a new developer, but even then that is an absolute trap imo, much better to take the time to learn a more robust engine from the start