Actually, Mortensen was highly acclaimed in a couple of David Cronenberg roles, while the hobbits mostly appeared in smaller parts. Blanchett and McKellan were long-established before LOTR. Andy Serkis is still doing the kind of stuff he was doing before LOTR.
Of all of them, Mortensen got the biggest boost, after Bloom, who is typecast in those kinds of roles. (His only major attempt at a non-swashbuckler/historical role was a huge bomb, Elizabethtown. Mortsensen wasn’t known by anyone before, now he’s at least getting the kinds of parts that earn actors some respect, if not much box office. Of all those who did the movies, if I were an actor I’d rather be in his position.
I liked that movie!! While we were watching it, on DVD, our youngest son was in another room. When he heard Paula Deen talking, he walked in and said "Mama, that lady sounds like you!" ;o)