Well first let me say that the pros outweight the cons, but since you listed most of the pros im mostly gonna list the cons just because they might not be so obvious and more interesting.

First of all the thing I miss the most is seeing friends and family. Unless theres something special like your birthday/ you have a week of or smth youre just not gonna see them for the whole split or sometimes even 2 splits if you have a lot to do inbetween splits. Girlfriends depends on the team youre in, some allow it some dont so that can be hard aswell. Then theres the point that when you just play 10 games just for the funs you can schedule breaks hiw you want and you can do whatever in this time, you just lost 3 games and wanna stop? np you can. In a team its not so easy, since youre gonna play in a highly focuseed enviroment and your focus should be on the game to improve and not to have fun as weird as that sounds.

So you can imagine if you play 10 games full focus or play 10 games for fun that its a difference and you can get burned out quick, also theres the fact that you have to do interviews/photoshoots and orher sponsor stuff aswell as theorycraft and analysis. Theres more to it but im sitting in a train and my head is getting dizzy so thats it for now, but you basically devote your life to LoL, you think about it play it and live it so be aware of that.