Personally, I don't consider Rise among the very best looking Switch games; to me that tier belongs more to games like Luigi's Mansion 3 or Mario Odyssey. Rise does look good though, just a little too blocky/flat in some areas of the environment to be a contender for the very top shelf in my opinion.
How is the framerate?
According to Digital Foundry's measurements, it runs smoother than MH World did on base consoles.
This is where we're going to have some disagreements lol... But civil discourse is always welcome!
Super Mario Odyssey is out of the question to me as a competitor: it doesn't stand up to close scrutiny at all. And it shouldn't: it targets 60fps. It relies heavily on artstyle and animation which leads to your second one.
While I also talked about Luigi's Mansion in my video about using an mClassic, Luigi's Mansion 3 WAS the best looking game on the Switch until Rise. Luigi's Mansion looks damned good, but not only doesn't even come close to the amount of on-screen action, but it also doesn't even touch the amount of alpha effects in use in Rise. Then, to top that off, Luigi's Mansion 3 relies on a static camera, isometric views, and half-frame rendering to keep its framerate up. A lot of people don't notice stuff like this, but I do. You can record and closely inspect footage, and you'll see it "ghosting" from the half frame rendering. Rise runs natively, while doing quite literally dozens upon dozens more things on-screen at once, all with alpha effects. This also leads into that last part...
When it comes to end-game hunts, I don't think Digital Foundry gave everyone a good representation. I checked that video out a day or two ago after I uploaded my review for today, and while I didn't watch it minute-for-minute, he did not in any way show what most MH players will do in the endgame: hunt in full parties. It's a TOTALLY different ballgame with four people popping off hard on a monster while the monster is flailing about, and I guarantee when/if you see this, not only will you notice the framerate starts to dip, but you'll probably recognize why this is the best looking game on the Switch lol
How is the framerate?
For me it has been a solid 30 fps 95% of the time. However I cannot speak for full group hunts, as I have been playing solo. As soon as I finish all the Village Rank hunts (on the last tier now), I will takle the hub and dabble more with the online. I did do a few hub hunts early on, and had no issues.
Yea, solo'ing is very different. When you hit those hub quests online in the endgame high rank stuff when everyone's starting to whoop out solid builds, things are happening at a level that makes solo'ing seem relatively "boring". It's what keeps the game surviving so long, and is why Capcom will be undoubtedly bringing harder monster tiers/variants as well as more monsters. It's what kept World going for so long once they brought Arch Tempered elder dragons around!