My 1970 car has a lap belt only and I use it.
Anyone want to guess how often I get stopped?
Every day? (Just joking.)
I know what you mean. I have a Datsun 240Z (1972) and the chest strap can be detached easily from the lap belt. Whenever I get pulled over and reach for the glove compartment, it comes off.
Probably should replace it only it isn’t frayed or broken. I hate to replace good stuff.