This is not a decent car. You are comparing an e-bike that is likely going to be bought by someone rich with a car that is likely going to be bought by someone poor. Also, China has plenty of e-bikes that are really cheap (and finding a decent one for $4k is really hard, it will probably cost $8k over there).
Particularly given the fairly smooth ramp from Walmart special ($100-200) through to entry level "good" bike at a sporting goods store ($300-600) to an actually-good specialty bike store bike and ultimately pro-am ($800-$2000+). And across all these tiers, there's typically a robust second-hand market in most places, though at the higher levels you'll find it via local riding club forums and so on rather than FB Marketplace.
It's an industry that could use some disruption. Maybe it's too old-school a business though, and the margins are too low for today's entrepreneurs.
The batteries are sold at a massive markup.
I also find standing up for my 15 minute commute far more comfortable that the hard saddles that seem to be in fashion on bikes these days.