From what I've seen, League of Legends is slightly more accessible than Dota 2, both in terms of overall game depth, and in terms of fanservice, with more female objectification and custom hero skins unrelated to the general game background. I'm not surprised it generates more fan engagement, but on the other hand, Dota 2 offers about ten times bigger cash prizes during their own annual tournament, so both games clearly are on different levels.

I'm not sure MOBA could easily be adapted to turn-based since some of the appeals of the genre are the mechanical skills, the split-second decisions and the heads-up plays in asymmetric vision situations. There has been some forays into FPS MOBA with Paladins, Battleborn, even Natural Selection 2 to some extent, but to my knowledge none have the same popularity or gameplay depth that either Dota 2 of League of Legends have.

And the major difference with regular CRPGs is of course the lack of progression save between play sessions in MOBAs which isn't easy to transpose.