These were very reliable and the way most software was distributed for greater than 20 years with few problems. They got a bad rap because around 2000, the quality of both the drives and media declined because at this time, they were only used to boot the floppy that would install the OS ultimately from a CD-ROM.
Good quality media and drives are OK. I keep several old machines around as toys and probably have hundreds of floppies which I sample periodical and are basically "fine".
There's also the issue of people getting into "retro" computers and buy floppies off Ebay that were low quality and stored in unknown conditions (a barn in Texas, etc.). My oldest floppies I own were from from 1983 or so, and are still readable.