Was cassette tape storage more common in Europe than the U.S? I’m too young to have been around for this era, but I’ve just never seen it over here.
The Amstrad CPC 464 had a tape drive integrated into the chassis (the 6128 used a 3" floppy - not 3" 1/4, a 3" disk).
In the UK and Ireland, in the late 80s, the majority of games software in computer shops was for these two platforms (much cheaper than a PC), with a handful floppy disk stuff for PCs. Consoles came in from the toy shop side rather than the computer shop side.
Perhaps it was similar with the Spectrum?
It also makes some sense that users in the East Bloc would have trouble affording expensive hardware.
As a result, there was a wide range of unofficial floppy disk addons, which then brought the issue that there were so many competing products that supporting them all was near impossible and hardly any commercial software bothered.
Post main-popularity, most people settled on the Beta Disc / Beta 128 from Technology Research as being the main unofficial standard, somewhat bolstered by it being adopted in eastern europe and russia, but during the main popularity period, even it had really poor market share in the UK.
* There was also the cartridges for the Interface 2, but that's a different beast entirely and they were even less common than the Interface 1 + microdrive.
** of course there was the Spectrum +3 near the end of the spectrum's life which had a built-in 3" amstrad drive, which saw reasonable commercial support, but it was long after the main portion of the spectrum's popularity, and at a time when the ST and Amiga were beginning to dominate.
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.