And even though they're heavy and bulky, it's much more tractable to install that infrastructure at a few dozen key airports, and also to manage the tracing/ownership of "fleets" of batteries.

Battery swapping has repeatedly faceplanted when it comes to cars, but it's a pretty different scope of challenge, and it seems like every major issue is more favourable to aircraft.

On the other hand, planes are often on the ground for 2+ hrs between flights anyway, so maybe it could be realistic with enough power delivery capability to just charge a big pack in situ. Certainly simpler to plug in a big umbilical at the gate than having to have another ground vehicle reaching into the belly of the thing.

Absolutely not. Airplanes have to be aerodynamic, and it would be incredibly challenging to make the entire bottom portion of the plane something that can open up and fit a giant battery. Never mind the weight of the whole system plus battery. The whole idea is absurd and completely impractical.

Batteries power will only be feasible for short-haul flights, and those have much shorter turn around times. Southwest Airlines has it down to 35 minutes. Recharging within that time limit might eventually become feasible but it's going to take some further battery innovations.