Pro of derailleur’s e-bikes: their price.
[waited long time to do that] - a former bike mechanist
edit: the problem with faster wear isn’t the risk to break but the decease in efficiency which will affect your motor health (heating) and batterie capacity. If you’re on a budget there’s a compromise: find your favorite gear and replace the derailleur and cassette with a single speed front and back sprockets (and chain). Beware that might not be adapted to hilly roads as GP environment.