Is Dota 2 any good?

I'm a long time player of uh.. that other MOBA and I am not happy with the state of the game there because they added a lot of champions which just ruin the experience by how unfun they're to play against, both in lane and in team fights.

Does Dota 2 suffer from the same?

Do you think Dota 2 is in a good state right now?

I play mid lane and I was wondering how's the mid lane experience and can a person solo carry games?

Also, if you have any good resources for a beginner to learn from, please let me know.