Nice thoughts!

I would say the primary development narrative of Rise isn't classic vs. modern MH, but mainline team vs. Ichinose/portable team. Rise is the Ichinose philosophy of expansive player movesets, very "designed" monster AI, and less grounded tone (seen in P3rd and Generations) taken to an extreme. This style has some upsides especially for monsters, but I've soured on it more and more as time goes on.

A huge reason Monhun has such deep and enduring combat is that the frame data fundamentals are very well balanced, ex. enough roll iframes to allow for dodging attacks, but few enough that the timing and direction is important. The Rise (and Generations, and World to a lesser extent) approach is to just give players more tools to mess with, but that risks breaking the delicate balance so that the player falls into a spammy playstyle. I love Gunlance in SB but Bullet Barrage is such a powerful, easy to spam move that I just don't use it so other moves can shine. This is not to mention the increasing amount of parry effects, which are a very poor fit for MH's highly telegraphed moves, simplify defense, and tend to be spammable damage options.

Re: hunting genre, I would agree and go further by saying that none of these games have meaningfully achieved the experience of being a hunter surviving off an ecosystem. The closest attempts, MH1/2, end up as this pseudo-MMO grind thing, and ever since then the games have basically given up on trying. As a result Rise has huge amounts of vestigial bloat systems from 20 years ago that only bog the pacing down at this point. IMO they really need to rework the whole structure in a more organic way (a la Rain World or something), or just actually give up and make the game a boss rush.

I think the 30 min session ideal is a great idea and would love to see it again, but in a more refined package that is closer to classic MH combat.