It was one of the reasons for buying a R+M Superdelite and it has been great, the tensioner pulley means no adjustment needed in 4000km so far, truly maintenance free. I have a crank drive hybrid and MTB and the wear rate on chains and cassettes is appalling even with careful maintenance although I do cycle year round in all weather. I wash the belt when cleaning the bike, just hosing it off (subject to hose pipe bans of course). On the other hand the chain on my rear hub motor Orbea looks as if it will last for ever!
Rear (and front hub) drives, relieve the chain from having to pass motor torque, which I have also found dramatically reduces stress and wear on conventional chain driven e-bikes.
I forget now the exact number of Kms, but on my first e-bike (bought 2nd hand, rear hub), I replaced the chain and the cassette with well over 20,000 KMs, though the cassette replacement actualy fixed all problems with the chain dropping off occasionally....
A traditional bike chain was never designed to handle both human AND motor torque for long periods.......
I have friends in Germany that rarely achieve more than 2,000 KMs on a chain (are ecstatic if 2,500 Kms is achieved!!), and are still happy!!!!
Its apparently become the accepted norm for certain German (sold and named, but not made!) e-bikes with mid motors!!!
regards
Andy