What's the alternative, though? Removable panels will be more expensive, and troublesome in various ways.

Drywall is not too bad to deal with. And 99% of the wall surface doesn't need to be opened for a -long- time.

I watched a video recently, which I can't find, where an architect set up a beautiful wooden baseboard around the entirety of their property, and that baseboard held all mechanicals and was perfectly clean and easy to get into as needed.

Drywall is manageable and cheap, I agree. But it's more painful than it should be for something that _will_ require maintenance.

This sounds great but violates all the building codes for a variety of reasons: eddy currents, risk of electrocution if there’s a short somewhere, noise in telecom cables, etc.

Mass production should be able to make this standard. Walls don't vary that much.

Personally I've been printing snap in access panels whenever I have to get into a wall these days - in white PETG they pretty much disappear into the wall for me.

Odds are you are compromising the fire safety of your residence by doing this.