I dont know if this is a fair comparison to make, but in my mind, these are the two most popular sci fi and fantasy settings respectively. And at least fill that hole in my mind of "classic fiction action-adventure trilogy" of movies. But to me the star wars og trillogy setting feels so much larger and LotR feels so much more constrictive. At least for RPGs and wargames.

the events of LotR feel like they happen very rapidly one after another, while there is much more space between events in the star wars trilogy. like 10 years of empire at its hight before the first movie is set, like 2 years between 1 and 2 where the alliance is building up after the destruction of the death star, then another one before the battle of endor. thats like 13 years were you can get things set in the "overpowered empire, scrappy rebels, and smugglers" setting. While all the events of LotR happen over like a year or two. and most of the big things happen days apart, like the rohirrim joining Ghondor or the revelation of Sarumons betrayal. where you get a few months time of "the united free peoples of middle earth, powers of darkness, and travellers".

ps, yes not talking about eu or silmarillion + hobbit