[csydas]

>It's not like the case of football, where you need friends and you need to go out to play

In fact this is part of the problem. the Dota-like/MOBA genre indeed has decent match making for the major games, but having a team you know, are communicative with and have a long/deep experience with one-another's playstyles helps immensely. I only really played League, so I can speak mostly towards that, but it's a different game queuing with friends than it is queuing with randoms. A lot of the excess communication required for a smooth match is removed when you have established a "sense" of how your teammates will react to situations, and it changes your judgement a lot when you no longer have as many random variables to consider during team fights, ganks, etc.

Watching pros play does a few things as well; you see not just good strategies, but mathematically sound and consistent strategies, which make the times you do play much more fun since a lot of your guesswork is removed. Pros also tend to have the skill for higher performance, and you get a chance to see pretty unique situations and plays that just never happen in ranked/normal queues. Plus, the pros have a huge audience typically, and you respond with the audience; being excited about an awesome play is amplified when you and thousands of other fans are collectively "losing your shit" over a play.

So yeah, you can go solo in such games, but the experience is always better with a team of people you know and can trust, and you end up in the same situation as football where you need to find others.