In terms of Sonic, I think the boost gameplay is fine when it has the level design to back it up (which Forces kinda lacked,) but... in a practical sense, it seems like Sonic games are slowly having smaller and smaller budgets (notice how short the levels in Forces are, plus the game couldn’t even muster enough content to be a full price game) and the boost gameplay requires a disproportionately large amount of level modeling for how much gameplay it presents due to its speed, so, if they want to have levels with notable length ever again, they’ll have to try something else that’s a bit slower.
I feel like the 2D sections in Modern Sonic’s parts of boost games are overhated, though. When balanced out in a level properly and designed well, they allow different parts of levels to have different kinds of level design and hazards in a format that better fits them while retaining about the same gameplay and controls for both formats.
Edit: In terms of gadgets, well, I do think Sonic doesn’t really need them and he’s represented well enough without them. At the same time, though, I’d personally rather either side special or down special be changed just because the differences between them are so unintuitive, so, one of those theoretically could fit in. So... the rolling moves are fitting representation, just not good design. You shouldn’t really have to look up the difference or experiment a bit to find the difference when it should be intuitive, right?