I think you are conflating assembly language vs. C and cross vs. native development. All four combinations were possible and all were used in the early 1980s t

I think you are conflating assembly language vs. C and cross vs. native development. All four combinations were possible and all were used in the early 1980s too. Cross-assemblers, native assembler, cross compiler, native compiler. Not everything was a C64 either, but in that example and other early home computers, game, graphics, music tasks required hand written assembly to squeeze out every last ounce of performance and code size. Whether that was cross or self-hosted probably varies. The choice of cross or self-hosted development probably depends much more on the availability (or non-availability) of a self-hosted toolchain (assembler or compiler), and the availability or not of a host machine than the performance.