[boltzmann-brain]

These ports are not really "hard wired". They're modules that fit into the mains plug well/niche, just like any other thing that fits in there. They can be changed for anything else once they become outdated, you just shut off your mains, unscrew three wires and put the new thing in. But they probably won't become outdated, because:

1. the USB C plug is here to stay for a longer while

2. with 240W we've already reached power delivery levels that exceed most small appliances you'd want to hook up like that; most larger appliances will take mains. 240W is a practical limit because if you go much above that, the consideration isn't really how much power can your device suck out of the wall, the consideration becomes: if you hold this thing in your hand, will it burn you? You can't escape the physics: 240W power dissipated means 240W power coming out of your device as heat.

3. we've just reached a new, more reliable and more power efficient semiconductor process (GaN) which only happens once every decade or two, so anything made in the next 20 years or so at the least will have roughly the same kind of performance, and anything in the next 50 years or so will probably not exceed it by unacceptable levels