The blame is on the engine as I said above all else though, not the developers of the games really (unless you want to blame for the choice of engine I geuss). RPGM have always been behind in resolutions I am pretty sure(wouldn't be surprised if MZ (that was released in the autumn 2020 were still stuck at 720p or something, not sure on that one though, no intention of buying it just to try and find out that
), and to make matters worse, you have to buy each new version separately, for a pretty hefty price. It really is a pretty limiting engine. I am sure most of the developers using the RPGM engine actually draw the pictures at a much higher resolution, but then have to scale them down to fit the engine. The only thing to me that RPGM seems to have going for it is the fact it is a bit easier to start out than the bigger engines like unity or UE, but in the long run anyone trying to make a game would be way better off starting in one of those engines from the get go anyway imo, as the potential is so much bigger, and you can actually make a game for free on them as long as you don't earn more than a certain amount from it (can't remember the exact amount)
Sorry if that got a bit too ranty
Weeeellllll ... dunno bout that. I very much agree that the potential is higher if you go for Unity or Unreal, sure.
These are professional engines and you can build anything from a little card game to Dragon Quest to Final Fantasy VII Remake.
However, the learning curve is generally ginormous. The thing RPGM has going for it is, for as far as I can tell, it's 'ease of use' and the ability to produce games with out of the box resources.
Sure, it leads to a metric ton of generic, samey games of course, but you can get a game out w/o too much technical expertise. And, as far as these types of games are concerned, the people making them will generally be artists first (rather than techies).
So I'd say the popularity of RPGM in this space didn't just fall out of the sky.
And really, if you're really willing to go the distance, you can get a lot done in RPGM as well (see Kagura's latest release, Evening Starter for example, which was a 3D dungeon crawler in RPGM, which is likely not very out of the box
).
Anyway ... you'll also notice that most, if not pretty much all, Unity/Unreal choices go there because they wanna produce a 3D game rather than your typical 2D Turn Based RPG we're used to getting from RPGM/Wolf. You'll rarely see a straight up 2D Unity game ya know.
Once again, that makes developing these things much harder if your primary goal is to just present the player with 2D CG and not spend too much time on the 'game' part (there's lots of these, as you know).
But even if they don't wanna just skimp out on having a proper 'game' part ...
Unreal pretty much requires you to know C++ and Unity is C#. This makes Unreal the most difficult of the 2 to get into by the way, despite arguably being the stronger engine of the 2 for making the most high end stuff.
Sure, both of them have some extra tools to get you started, from what little I know about it, but still.
So, also a bit too ranty I guess, but to conclude ... I get what you're saying in regard to the professional engines being capable of more, but I really do understand the appeal of the RPGM framework to artists.