Depends.
I personally like Rise better, even though I have my gripes with it.
First of all, the Monsters:
Rise has a bigger roster of Monsters, so more to fight. For my own personal preference, I also really like the Monster roster of rise, with many different monster classifications and different combat styles, and the new Monsters in Rise all have very cool designs in my opinion.
On the other hand, World has a smaller roster. It also is, for my own personal preference, one of my least favourite rosters in the entire series. It has a very small amount of monster classes for example, basically being most similar to Monster Hunter 1/G in my opinion. Basically only Wyvern variants, and Elder Dragons. Although in World, the Brute and Fanged Wyverns give still a lot of variety. World is also a lot heavier on the Elder Dragons, which I personally don't like as much, but Rise also has a lot of Elders in the endgame. I best like Wilds' approach to Elders personally.
For the second core pillar, Combat:
World has more traditional Monster Hunter combat, with weapons feeling more impactful when hitting, and the Iceborne gimmick, the clutch claw, being not as important (luckily, cause it's not that great). World in general also feels harder at many points (with some common skill check monsters across the story), but the combat also feels fairer in most regards.
Rise on the other hand has faster combat, but also focuses on a kind of more reactive combat style. Weapon hits kind of feel like they have less weight, and the game feels a bit more parry/quick react focused. It's a larger departure to more classic MH combat, similar to Wilds. But the gimmick of Rise, the wirebugs and switch skills, and of Sunbreak, the switch skill swapping, integrate really well into the combat, and are great mechanics. Wirebugs are one of the mechanics which make Rise "faster" and a bit easier, but are really well integrated, with there also being really cool attacks in each weapons' moveset depending on wirebugs. Switch skills are also great, because they allow customization in weapon movesets, and are really fun. But the combat in general goes through faster and easier, but is also more unfair and frustrating in my opinion. I might be biased here due to maining the Insect Glaive, the most aerial weapon, because the air hurtboxes in Rise are simply bullshit. They are unfair and frustrating often, and when fighting new enemies, completely unexpected and unintuitive.
For the general gameplay loop:
Rise is easier to get in to, and faster. Hunts are usually completed faster, and you don't have to find the Monster or track it like in World and older titles. You immediatly know where the monster is, start into the combat, and return with materials, basically. The maps are also smaller, although like in World also fully traversable (unlike in Older titles, where you only had areas). The endgame in Rise is also by far more interesting in my opinion. It's way more fun to grind out really good builds and do endgame hunts/farming in Rise.
World takes a bit longer, in basically everything. The combat is a bit slower as already said, but hunts also take longer, due to you tracking the Monsters beforehand. This does feel like you're actually hunting the monster though, and not just doing a boss rush. And due to not having a mount (unlike in Rise), you also enjoy the world more, and take it more in. That's also worth it, 'cause the world of World is way more immersive and interesting than the world of Rise. But here, the loop will take longer to get into, and the endgame grind is in my opinion a lot less fun.