Genji can't dance on Overwatch 2's payload and it's not right that Hanzo can

techradar.com:

Overwatch 2 is fresh out the gate, and there’s a lot to be excited about. So why have they taken away what is special to me: my ability to dance on the payload?

Emoting is a fun and silly way to engage teammates and enemies alike in Overwatch 2. It can also keep you entertained when you’re left to babysit the payload and push the cart to the objective while your team is out fighting your opponents on the other side of the map. As the payload won’t move without someone near it, one team member will often be left behind to do God’s work.

And what better way to while away that holy work than dancing on top of the bomb?

It turns out that while some characters retain the ability to bust some serious moves, others suddenly seem too shy to take center stage on the payload. Take cyborg ninja Genji and fleshy ninja Hanzo. While Hanzo can pull out his ‘fisherman dance’ on the payload, Genji is left slipping and sliding off the cart every time. 

It seems as if parts of the geometry of the payload are treated the same as what’s used for the roofs in Overwatch 2. By this, I mean that any surface Blizzard says is not ‘flat’ or should not be accessible causes your character to slide right off it. This mechanic is a good way to limit access for curious players who want to explore each map's forbidden corners.

This means that Genji can stand on the payload and sit on the payload, but as soon as he starts dancing and his foot taps one of the parts of the payload that is curved, he freezes and slides off, like a chump.

Genji's passive ability, Wall Climb, lets him scale any flat surface, so long as it's not been marked as inaccessible, but it appears Blizzard has been quite liberal with surface tagging to keep the ninja grounded.

A good example