Dunno man,
If the current trend in geared hubmotors continues, at some point in the not so distant future something equivalent to a 4X clyte or somesuch will show up. Except, it's gonna weigh a fraction of the 4X so it won't hurt the bike's agility anywhere near as much, a major advantage for everyone who actually enjoys riding bicycles. It'll be smaller and will likely actually fit bicycles and blend in as a bicycle component, by opposition to the typical gaudy chunk with a crude finish that matches nothing else on a bike compounded with DIY torque arms that stick out like an afterthought... Ugh. Cherry on the sundae is it's going to be more efficient, likely matched with a smaller controller that's also more efficient. I expect people are going to want to move away from current designs even if they still work, I know I would. Maybe ROI weenies wouldn't.
History has a way of repeating, people ditched friction drives that still worked fine in favour of things like hubmotors. More efficient, faster, less clumsy, less ugly. They're worth next to nothing on ebay, and I bet a lot of them still work but are rotting somewhere in a garage or barn, if not in a dump.