Redditor claims that Monster Hunter Wilds runs better 'the more DLC you own', and it does—but not by much on my machine
Monster Hunter Wilds is somewhat infamous for its performance woes, leading its Steam user rating to drop to "Mixed" since release thanks to a host of reported technical issues. However, redditor de_Tylmarande recently posted a potential fix—a homebrewed mod that skips a DLC check, which is said to massively boost performance.
They claim to have first noticed the performance improvements when swapping between a friend's account with all the DLC enabled and their own, and noticing that the game ran significantly better on the former.