Your description of it sounded Sisyphean

You CAN get better at DOTA2 by playing it, but you need to play with some intention around building skills, be okay with losing as you learn, and be honest with yourself about how you could have played better instead of raging at your team after a game.

I don't think dota is inherently more Sisyphean than any other competitive game (or game without a defined ending point, really).