Essentially all commercial programs released for the 6502 were written in assembly language. Modern compiled languages like this hope to get close to the speed

Essentially all commercial programs released for the 6502 were written in assembly language. Modern compiled languages like this hope to get close to the speed of hand-optimized assembly language while making the code much quicker and easier to write and modify. At the time systems like NES and C64 were popular, this would absolutely have been relevant. The time schedule for delivery of games was often extremely tight, and anything that would have let developers accomplish more in less time (with fairly minor compromises on execution speed) would have seen strong usage.