What you let slide in yourself becomes what the whole team thinks is normal.

The worst thing that goes uncorrected is what defines a standard, and the version people learn is the one they watch you allow. Whatever you excuse in your own work becomes the practical floor, whatever the stated expectation says, because nobody holds a line the person in charge is visibly not holding. The slippage is rarely noticed while it is happening.

Find the one thing you have quietly stopped doing properly and start doing it again, without comment. Expect no acknowledgement for it. The floor moves back up on its own within a few weeks.