I think it's a lot to do with the pacing of the games. Rise is a lot faster, World comes across as much more slow and methodical. Saying that I do enjoy Rise a lot more than World, which I always bounced off of and couldn't get in to.
If I wanted to spend 30+ minutes in a game tracking monsters through bushes then killing them with traps I'd play Rising Storm Vietnam.
Tbf Rise also makes you run around catching Spiribirbs. If you are on pc there is a mod to bypass that but otherwise it becomes a chore when you have grown accustomed to the map.
Gonna break it out into a few subsets of people who would prefer World to Rise (not saying these are the only reasons or that I agree with them):
People who really value graphical fidelity/spectacle
People who really enjoy the ecosystem cohesion aspect of World (maps being less arena-like and monster-design being slightly more "grounded")
People who disliked the switch skills in rise
People who dislike the wirebug's combat changes in Rise relative to the World/Iceborne system
People who dislike spiribirds and don't want to use mods
I wish that Rise would have leaned into heavy combat changes/options more (like Generations Ultimate did) instead of having them be cooldown-based skills (think valor or adept styles in that game specifically), but I think by the time Sunbreak hit that they'd made interesting enough play-styles for Rise with switch arts allowing you to do some fun things.
Personally I prefer Rise to World (I loathe the clutch claw's tenderizing skill and think it's the single worst combat mechanic in the entire series), but I still heavily, heavily prefer MHFU, MH3U, and MH4U to all new generations game. My specific reasoning is I feel that the combat has moved from prediction-based in the core combat loop to reaction-based (GU adept style not-withstanding in my personal critique).
I imagine most players in the franchise (which is overwhelmingly new fans due to the success of World and to a lesser extent Rise) care about the bullet points listed above as well as have their nostalgic first experience in World leading it to be more popular than Rise on a whole.
Also if you're ever open to playing the older games let me know and I'd be glad to answer any questions you could have (multiplayer is available in MH1, MHG, MH2, MHFU, MH3U, MH4U, and MHGU through emulation).
Monster Hunter 4 Ultimate (3DS-Citra) or Monster Hunter Generations Ultimate (Switch - Ryujinx LDN build so you can play multiplayer). Generations Ultimate is a switch port of a formerly Japan-only 3DS game (MHGU is the English release) so if you're worried about emulated Switch performance it's one of the easiest to run games on that console.
MH4U is probably the best way to play the fully realized vision of the oldschool formula (mechanically it's "complete" in this game) and MHGU allows you to to either play with MH4U mechanics (Guild style in game) or with various twists (Valor, Adept, Alchemy styles) which radically alter the combat style of each weapon. I played through the game first in Guild style (because I didn't speak Japanese and only had that version at first until the international release) and while the game is completely beatable never using any weapon styles/hunter arts, the post-game content (Deviant monsters) are absolutely designed for you to use those things.
If you had to make me just make a gut call on what to try- I'd say MH4U.
If playing MH4U you might want to use the following cheats in citra for QoL:
[Increase camera rotation speed]
00BFD2EC 41A00000
00BFD2EC 41A00000
00000000 41A00000
[FOV 60]
00C06D98 42700000
00BFF614 42700000
00BFF618 42700000
6105729C 00000000
B105729C 00000000
00000ED0 42700000
[Disable 3D]
610572CC 00000000
B10572CC 00000000
00006BA8 011F036E
D2000000 00000000
This is done by launching the game in Citra and then clicking Emulation -> Configure Current Game -> Cheats
If playing MHGU on Ryujinx LDN you may want to use the 120fps-v1.4.0 patch by theboy181
If you need/want further clarifications about anything let me know and I'll be glad to help. Also if you do decide to play one ask questions early and often (I'd also be down to play if you're ever interested). The older games start much slower. They usually give you some busy work quests (collect 10 special mushrooms, kill 10 small monster) before you really start getting into the core gameplay loop that you're used to in Rise. It usually takes about 1.5-2hrs to get to that point.
Also note these games are harder initially due to just different mechanics that you'll get used to. You have limited health potions; no restocking at a base camp- what you bring and what is in the supply box is what you get. Once you unlock the kitchen you have to eat before going on a quest as there's no in-quest kitchen available. To mine/catch bugs you need pickaxes and bug nets in your inventory (which can break). I've had pretty good success in getting new world players (World and Rise) into older games, so if you have further questions really do please ask.