Well, carmack is THE game dev of 90s and 2000s fame. His 2d/3d engine work was outstanding back in the day.

Bellard did multiple breakthroughs: ffmpeg, qemu, tcc, jslinux, a state of the art FFT algorithm. I probable skipped a few.

With all due respect to carmack, a single ballard's projects would put anybody into the eternal hall of programmers fame right next to Linus, Carmack, Stallman, the Bell labs crowd and others.

i do understand how carmack did what he did logistically (time, effort, skills, compensation)...

Fabrice is just out of this world. When? How? Why? No idea.