Games are hosted by a player on a proxy server.
Players joining can be on a completely different proxy server.
The two proxy servers then communicate and you see the result. This is how they do OverWatch and it is also how they managed to get OverWatch to work regardless of your ping (their buffer is extremely effective). Sadly, it has not - so far - worked for Warcraft 3.
Part of the issue is likely that the host can get any of the 4 places in the world as Proxy server and so can the players joining. Meaning a European host can get an NA server and play against a Chinese on an EU server - should really just limit it to be region dependent instead and then we can listen to the amounts of whine about the queue time being atrocious instead. There’s not really any way to please people.
Well, game connecting me to a game where I have constant 500ms ping is more time consuming than the queue time. It is literally unplayable.
I would rather don’t play if I am gonna connect to those games. And this is happening almost 50 percent of the time. I stopped playing it and started to leave those games.
They should consider about “what a good maximum ping would be” and limit the matchmaking according to it instead of disregarding it completely. Thinking about this and fixing this should not and would not be hard.
Buuut they have more important things to work on right now I guess.