Hydrogen is a dead end. The only company left trying to chase that particular dragon is Toyota, and I predict eventually they'll be forced to admit that it'll never work en masse for private vehicles. Ordinary consumers can already barely be trusted with gasoline, which is neither under high pressure nor requires industrial grade refrigeration to keep it in liquid form, and is a lot harder to ignite... The delivery systems for hydrogen are extremely complex and must maintain an absolute 0% failure rate or else somebody will either get blown up or frozen to a pump. Gasoline is at least a liquid and behaves predictably when spilled, and doesn't phase change instantly when it leaves containment. And a mechanical failure in the delivery system can be mitigated by simply shutting off the pump. You poke a hole in a hydrogen filling system and you're going to have a very interesting time. Current systems have redundancies on top of safety devices on top of redundancies for this reason which makes them fantastically expensive.

Hydrogen also has crap for energy density (around 8 kJ/liter in liquid form, compared to 32 kJ/liter for gasoline) and even if you're producing it via electrolysis or something is a wildly inefficient way to store and transport energy. If you're going to use electricity to create and compress hydrogen to transport it and create electricity with it later, it is monumentally more efficient to take the electricity and put it in batteries. So you may as well just to that.

The thing with battery swapping is that it will absolutely require strong government regulation to ensure standardization and fair treatment of owners. Replaceable batteries in consumer devices obviously aren't a new concept, and before proprietary lithium packs took over everything, every single consumer device was powered by AAA, AA, C, or D batteries which were very well understood by everybody and were -- and are -- completely interchangeable commodity items that are readily available to this day. That's the only way it'll work. Manufacturers will have to be forced to standardize on a set of pack sizes because without oversight they'll inevitably try to turn everything into a subscription-only walled garden pretty much exactly as you have predicted. But if there is a thing as an equivalent of an AAA vehicle battery (for motorcycles and scooters), AA vehicle battery (for city microcars, NEV's, golf carts, etc.) and C vehicle battery (full size passenger cars) and D vehicle battery (light trucks) etc., and nobody is allowed to try to make up their own bullshit, then no one will have to give a rat's ass about battery health, the dealership, lock-in, or anything else. If you buy a used vehicle with a knackered pack in it or your battery gets cacked, you could just bop down to your local AutoZone or whatever and buy a new one. Or push your car to the nearest swap station. You'll turn in your old one for the core charge. Exactly like how 12v vehicle batteries work now.

We'll have to get people used to the notion that, yes, these things will be kind of a battery lottery and you may get swapped in a pack that's in slightly worse condition than your last one if you go around pack-swapping all the time. But you know, the next time you swap you'll get a different one again. And you can play already this game right now if you want to -- just go buy some fuel in a third world country.