Earlier quoted context omitted.
I’m curious how you used it as a daily driver back then. Did you use it for internet access? Granted, JS was less prevalent back then, but I’m not sure what browser you had available. What about listening to mp3s while doing something else, could the m68k manage or are you just not doing those things normally?
Not OP, but if it was anything like Macs running on similar hardware - MP3s was not viable, simply not enough grunt. Also most (all?) MP3 decoders relied on a FPU unit to function. But CD's where fine.
I don't know which era of chip you're thinking of, but when I was a kid listening to MP3s, it was the late 90s, and I had a Performa 5200 with a 75 MHz PowerPC 603 (or possibly 603e); it had a FPU, like all PPC chips, and IIRC like the final series of 68k that Apple used, the 68040 which Wikipedia says was also used in some models of NeXT machine — my problem was MacOS and how it multitasked (cooperatively), making MP3 playback clip every few seconds if the player was in the background; and I'm sure it was the OS not the chip, because I later upgraded to a newer computer with a 200 MHz chip, and it behaved exactly the same way.