All hallways on the Enterprise and other Star Trek spaceships are unnecessary, bc everybody could just beam themselves from room to room. amirite?

They have site to site transport, It's primarily for emergencies.

To me this suggests that site to site isn't particularly safe for every day use.

They'd have to beam all the extra fat off themselves as well!

But it costs energy from the ship's systems. Walking down a hall is free and you don't need to wait for the transporter to be clear before your turn.

They tried in Spaceballs... good thing the hallways was, let's say, short...

Except of course if it malfunctions