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.
I've seen videos where people will put in removable drywall panels that can just be lifted out for access.
There are a lot of downsides though. You lose airsealing, if you don't have an airtight building envelope on the outside of the drywall. You lose fire resistance. You often lose aesthetics, although I've seen this done extremely tastefully. You lose childproofing, and run the risk of a kid electrocuting themselves or destroying your plumbing or dropping stuff in the wall. You impose constraints on what can go on the walls and where your furniture can go.
Given that drywall is pretty easy to cut and replace, most people figure it's just not worth the costs for something you do infrequently.
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.
You can absolutely put NM cable, etc, under a cover. It's just more trouble than it is worth. You still need the required setbacks from the wall, etc, and .. there's reasons why bored holes very low on the wall (like for a baseboard cover) could be problematic.
And for telecom / low voltage, you have a lot of freedom of how you do it.
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.
Drywall is manageable and cheap, I agree. But it's more painful than it should be for something that _will_ require maintenance.