I have gas bikes and do lots of cruises and meets. I'm not the ultimate authority on this but haven't seen any EV bikes with sidecars. There's actually very few motorcycle sidecars out there. I think Ural is the only one making one new for the US, not sure about other countries. There's some kits/aftermarket options though, so I'm sure it could be adapted. Sidecars are more of an iconic fantasy than a feasible mode of travel, though. It's nearly all of the downsides of a motorcycle (no longer have to balance and can't tip to the car side, but more prone to rolling over the other side) while not adding much positive besides a little cargo space and element protection for the passenger. A huge downside is awful crash results for the passenger. Bikes are the only vehicle where you'd rather be thrown from the wreck, particular when wearing armored gear. I would guess trikes with the rear dual axle largely replaced the classic sidecar use case while recent reverse delta trikes (two front wheels) brought up the rear with riders looking for a different scene. Touring bikes have come a long way as well and the prevalence of ac makes the comfort of cars more appealing than the thrill of bikes. Plus trailers and bike rental networks reduce the need to ride a bike the whole way to the destination. Maybe they're bigger further inland, but the only sidecars I see are vintage/craft projects at bike meets.