Lemmy faces the same expectations problems as every free/libre software
It's the same as with Linux, GIMP, LibreOffice or OnlyOffice. Some people are so used to their routines that they expect everything to work the same and get easily pissed when not.
I think that for Lemmy and Linux the problem is actually in the people using it. Without people using it, they won't be many posts/good software support. Without the posts/support there won't be many users. It's not some UI being different, or anything else. It's the main issue. When you see lemmy.world frontpage (All, not Local), there are 15 threads about Reddit and Lemmy, 2 about Twitter limits and the rest is about tech. Meanwhile, on r/popular you have variety of communities, still mostly memes and videos but there are also other posts.
It's more about reddit that reddit is. You can't make it long-term with this type of content. On other instances it's more bearable, but it's still not enough to keep people here.
Clearly you have never used Arch Linux then - Arch Wiki is truly marvelous.
Likely the problem is more with people not willing to learn anything new, unless forced to do so, because that will break their routines and many are aversive of that.