If the issue is creaking beams, then it really should be investigated. We used to own in an old building in Bondi where an owners downstairs complained about a sagging floor. It turned out the corner of the building was only being held up by an arco-prop because of subsidence caused by the run-off from a blocked downpipe from the building next door.
Yes, buildings get creaky as they get old – they also get creaky before they collapse. You might need new floors and that’s an OC reponsibility, at least to investigate.