That’s kind of why manufacturers are doing better than normal warranty ts&cs, such as restarting warranties when parts get replaced.
If that’s common I have no idea how manufacturers are making money. Unless the cost of manufacturing the bikes are actually very small and the profit margins are huge.
I wouldn’t touch the Bafang, and similar, kits with a 10 foot pole. Ymmv.
If I’m buying something that is going to break I think I’d rather just fix it myself than bring it back to the shop every time. From the sound of it Shimano, Bosch, etc are using a closed system whereas bafang is open. If that’s the case then bafang is the only sensible option.
Like I said, from the sounds of it the technology isn’t mature enough yet.