I had to actually get my hands on it to find out what appeals. For me it was a combination of challenge, routine, and a clear sense of progression. Hunting materials for gear gave me clear milestones while I was also getting better at the combat at the same time in a more intangible way.
Monster Hunter World was the one I spent the most time in, and my favorite part was the multiplayer. Unfortunately, frustration with that is also what led me to eventually drop it. Co-op with a friend in that game was bizarrely restricted, with a really janky way of going through the story (I eventually figured out that it was just better to do the story independently). On top of that, the multiplayer had technical issues on PC at launch.
I hear that Wilds will have a similar setup for the main story co-op–outright bizarre for a AAA game releasing in freaking 2025–but here’s hoping it won’t have the other issues at least.
Also the easiest way to play the PSP version with the combat slowdown fix, which is essential.