Nope.
i tried league for a few months when i took a break from dota, i got to level 30 then returned to dota after my friends started playing it alot again.

it's as fun, although i found it a lot easier. the hero skills in dota are much more synergic with its skillset while league skills are more like "this is a skill, it deals damage, use this with your other skills to deal damage"