Well, MMORPGs are all based more on D&D than on Tolkien. And then 4e took a lot of ideas from MMORPGs, some of which were retained for 5e, so it's become kind of a feedback loop.
To be honest, I can't recall playing a single RPG in any media that feels much like Tolkien, aside from the setting. And I started with MERPS in the early 80s. Tolkien's narrative is really hard to capture via consistent rules that promote class balance, etc. For example, how do you account for a wizard who has to hide in a tree from goblins, but can also go toe to toe with a Balrog?