Weight is definitely an issue if you want to carry the bike up a flight of stairs to your apartment. It also matters if you want a real cycling experience with the power shut off at times, and if you get caught out there with a drained battery. A huge, full-suspension fatbike on the street is just silly. Not that there's anything wrong with that if it's what you're into (I like them), but presenting it as a necessity for street ebiking is a bit much.

My next build will start as a steel 25-pound bike without suspension, then add a Bafang BBSHD. Light enough to carry upstairs, light enough to run at PAS 0 for parts of a ride.

Oh, and it will have a derailleur. There is no quantifiable difference in reliability or mileage life between this and an IGH hub: Both use chains and sprockets that will wear faster than a non-assisted bike; these forces have no effect on a derailleur's ability to move back and forth across a cassette. Plus it's cheap and easy to replace when the springs do eventually wear out. When a hub goes you have to rebuild the whole wheel.