I guess manufacturers assumed people will first and foremost use them to move data around, not to backup/archive it, which makes sense as they were somewhat pricey initially, while the role of "write once, read many" was occupied by CD-R discs.

Of course, at some point the prices dropped, and eventually some people ended up owning a dozen USB sticks of various sizes and shapes, some of which used for archiving, but none of them labeled.

Underrated point here. Floppies at least usually came with sticky labels so you could tell them apart.

With flash drives, If you're lucky, you get a colour assortment in the box.

I bought a packet of 5x16Gb drives, and I can't tell which ones are the "partitioned strange for use with a vintage machine" versus "my brother's backups".

Even with cassettes we used a sticker. The labelers know their craft.