I encountered Dragonlance before I read Tolkien, and years later in my teens was shocked to realize how much had been cribbed from Tolkien in it:
Heroic human with elven ancestry torn between his Elven and Human heritage, as well as between a human and elven choice of partner;
Irascible dwarf companion;
Legendary weapons brought back to light after being lost;
Secret dwarven paths through mountains;
Two groups of elves, one more aloof than the other;
A mage that goes from a "neutral" stance to an evil one;
A wizard who is more than he seems, and who "dies" after a fall from a bridge...
Etc etc etc etc
However, it still holds a place in my heart that Tolkien doesnt, simply because I was able to finish the trilogy at age 12, unlike my slog through Tolkien at age 15. I retried about 7 years ago and still didnt get past Bree.
One other thing Dragonlance definitely did in my experience was that it got more girls and women into fantasy role play, which D & D alone did not. I met at least 4 separate girls in high school who knew Dragonlance, but not D&D.