I don't think this is where peak battery tech ends up. At current capacities, batteries are becoming genuinely dangerous, and faster charging only amplifies the risk. Charging high-capacity cells outside a temperature-controlled charger is risky, and even reputable chargers shouldn't be left unattended — many workplaces ban it outright (it only takes one fire to make that policy). Phone batteries are the worst of it: highest power density, fastest charging, odd geometry, and tight space constraints. Manufacturers shrink the phone by offloading temperature monitoring and heat dissipation onto the phone's own electronics and housing — so replaceable, externally rechargeable batteries are tricky to design. IMO, swappable batteries were a feature because batteries used to suck. In less volume-constrained devices like cameras, swappable batteries still work — but you're trading single-charge runtime for that convenience.

This last point is actually a real killer, an easily swappable battery in a phone probably sacrifices >10% "maximum" capacity in lost space. e.g a phone with a glued battery can have 5000mAh but the same phone with a more durable battery connector can only be 4500mAh.