[atourgates]

I think you're right, though 2wd eBikes might be different.

Our local trail association currently uses a Rokon: https://www.rokon.com/ - for trail maintenance, and it's just about perfect for that application. I could imagine them replacing it with a 2WD eBike at some point.

[salty_biscuits]

It really depends on center of mass and friction coefficient. Most cycling situations are wheelie before wheel slip. Even on dirt and up a hill the rider can just shift their weight backwards to get traction. A powered bike is probably different, with lower center of mass.