Similar - 2021 MBP 16". splash of red wine on the keyboard and despite all the usual solutions a few keys don't work. Works fine with external keyboard. Apple Store: we can send it away to be fixed but you must agree to a charge of up to $1600 because we don't know how far the damage has gone. Me: It all works except a few keys. Apple: That's the deal, and actually we'd recommend its not worth repairing and you should buy a new one.
Sounds similar. Charging circuit on an MBA. Laptop worked perfectly on AC power. Battery health via various tests and Apple diagnostics, healthy, just 0% charge.
"That will be $890 to repair. Maybe you should wander around and have a look at the new MBAs."