Back in the 80s, data storage on cassette was commonplace for 8-bit micros, because disk drives were expensive add-ons. I know I used them with my VIC-20 and TI-99/4A.
I had a TRS-80 Color Computer and struggled with a cassette tape interface that was faster than many competitors but wasn't reliable for me. The disc drive I added was more expensive than the computer but it was reliable and could support the OS/9 operating system
https://en.wikipedia.org/wiki/OS-9
which was better than the MS-DOS I used later on the much more powerful 286 machine that replaced my Coco 3.