The drywall wall is stronger, heavier thicker stuff and sometimes doubled up. We also often use steel work as the studs (particularly good professionals) as it’s stronger and faster than wood to put up. Then all the wiring is in conduits, and it’s acceptable to put water feeds on the outside of walls in the room for servicing. Then it comes to our bathrooms which are proper wet rooms and usually built to a very high standard to meet insurance needs.

I watch a lot of building videos from the US, it’s eyeopening watching for someone used to better construction methods.

The construction of UK inner walls is even better, it”s often plaster applied on plasterboard/drywall usually by skilled trades. Very strong.