There's lots of reasons to enjoy LotR really. For me, the main reason is the way Tolkien treats the world itself. Most novels try to put your in the character's heads. You experience their thoughts, feelings, motivations... their inner lives.

Tolkien doesn't try to put you in the character's heads so much as their world. He lavishes the landscape with descriptions of landmarks, weather, scents and sounds. He places you right there with the fellowship walking under oppressively dark forest canopies or freezing mountain tops fearing to be hit by a giant's boulder toss.

And virtually no setting can rival Tolkien's world for sheer world building. A place that has a comprehensive set of stories from the creation of the world all the way up to the events that nearly end it. With fully fledged languages and bloodlines that go back ages. A lot of people love Tolkien because you can trace details through centuries or aeons of fictional history.

And sure, it's not like warhammer or the witcher. Those franchises tend to have gimmicks exactly because they needed to reach for something to differentiate themselves from what you call 'generic fantasy'.

I love those franchises on their own just fine. But for me the difference is that something like warhammer is like a carnival ride. Loud, flashy, fast, a need to find some new whiz bang to keep your attention. Tolkien is more like a David Attenborough documentary meets a historical document. It takes you by the hand as you wander this beautiful and harsh world with little need to wow you with flashy effects.