Maybe? It's not actually that wide, or high.
You can get around or over it pretty easy. I don't think I've ever tried doing it to the wall itself, but double-jump-mantling things has gotten me over it right away.
You can't double jump mantle the wall, it's slightly too high. Triple jump yes. However, even then it forces you into a more vulnerable position just to get a sightline.
Ok. I wasn't sure. I haven't attempted it for the reason you mention, the manttle is a relatively long animation so you don't want to do it while someone can pour damage on you.
Instead I've been using the surrounding verticality in the environment to play around the wall, which IMO is totally doable. (Though depends on the hero you're playing)
Yes it's powerful, but McG has a pretty weak ult so it all balances out (roughly)
IMO all heroes have abilities that will be OP in certain situations or just in general. One of the first games I played against Shiv was literally almost a tie, but they were on a 35 kill streak. So yeah, it all balances out for the most part. I mean, my favourite use for the wall is blocking Bepop's ulti essentially making it useless.
A Lemmy community for the upcoming Valve Corporation game Deadlock