The final years of 3.5" floppy manufacture were bad. I think the quality was tailing off from the mid nineties. But it could equally be poor quality of the drive manufacture as well.

Certainly 5.25" floppies from the late 80s and early 90s were nearly bulletproof in my experience. 1.2MB was a bit flakier than the 360KB though. All were still perfectly readable 20 years later, though at this point they all got thrown in the bin due to their obsolescence!