I think the key factor is amount of rides. On a one to one comparison, obviously an ebike is less work but how much more often are ebike riders riding?

I don't own one but there have been plenty of times in my life where I go somewhere ina car that's in biking distance but don't because maybe there's a decent hill on the way and I don't want to arrive sweaty.

The easy ride an ebike offers opens up more opportunities to ride.