Those sorts of terrible is what my OP was about.
One time I went to a fools on stools after work and the guitar player was retuning his standard tuning for every song. W T H!
He would chang chang on the new root chord and it would be ''out of tune'' so he would 'retune' sorta, to sorta suit the new chords. My poor ears.
Of course his saddles were all over the place. At the break I made him borrow a screwdriver from the barman and we fixed it. He was very grateful!
Side note, every used bass I have gotten has needed intonating. I deduce far less bass players than ideal are aware.