Nah, Graham broke everything he touched and wasn’t really very representative.
I have a belt drive on a Nicolai Ion GPI. Being a full suspension bike it has a belt tensioner to deal with the chain stay growth as the suspension compresses. It has done a total of 2465 miles on the original running gear except the belt tensioner that failed in short order and cost me a small fortune to replace with the completely different revised version. Mud is handled just fine as the Gates sprockets are designed to let it squeeze through. The belt can make a slightly annoying noise when very dry but I spray a bit of silicone on it to quiet that.
So, after those 2465 miles
Aluminium front sprocket – shagged but still working
Belt – worn, probably because of that shagged front sprocket. But still working.
Stainless rear sprocket – looks A1, I will continue to use it with a new belt
Maybe relevant that I’m not that heavy, about 72kg and a chunk of those miles were probably uplifted so not as much pedaling as you may think. I would guess the wear on an e-bike is going to be higher but probably still very acceptable.
However I don’t think the belt drive offers very good value. The parts are not that readily available in the UK and cost a premium. When compared to running a waxed chain as I do on another bike…the chain and sprockets can last ages since it doesn’t have to do any shifting and is way more cost effective. Price is all I have against the belt setup though