Could you please expand on this thought? I'm genuinely curious as to what you mean by proprietary.
I cut my teeth on an Apple ][ with integer BASIC one would load from a tape. (Later, a ][+ with built-in Applesoft Basic and a floppy drive.) I'm puzzled what you mean when you refer to proprietary prouducts. I had an Epson dot-matrix printer, a 110/300 baud Hayes modem, and later AppleCat modem (1200 baud, full duplex, oh yeah!), a time/calendar card. A few different no-name joysticks, etc. The Apple ][s expansion bus slots actively encouraged aftermarket support. Anyone could create a peripherial.
Software came from magazines, commericial sellers (back of Nibble or Popular Computing magazines), shareware, my own imagination, BBS downloads, etc.
I think in more ways than not, the experience with the Apple ][ was in common with Commodore 64/128 users. The industry was blossoming, and competing by offering wildly different solutions with a common core.