No one can answer to this question for you but yourself
I personally prefer right now league to dota simply because of dota 2 1 hour games
average duration of a game right now is 48 min which is just unacceptable for me (i prefer 38 or 42 min) and i prefer 15 min games of league rather than 48 min
if dota had 40 min games just like in 2014/2015 i would have played it way more than league right now because league's current game duration is cancer
one thing i also prefer in dota2 is icefrog, the godfather of dota2. the ultimate balance/design leader he can teach to every single league's rioter (except ginsoo) how to balance a game
Icefrog is the most inteligent man i ever saw in my life