See the comment by electroly. They actually know what they're talking about.
See, the FPS score is for the whole machine. The c8g gives you 8 real cores. The C8i gives you 4 real cores, 4 hyperthreading pseudo-cores. So for those two machines the c8g unequivocally gives you more absolute computing performance, regardless of the passmark single thread (on a single core) on the c8i being better than a single core on the c8g. And the c8g comes at a big discount as well.
That's...the point. The Graviton processors are cheaper per core, and lower performance per core, and you make it up in bulk. You get more performance per $ if you're okay with the ARM stack and your software is good with it, and this is basically universally true comparing Graviton instances versus Intel/AMD alternatives.
You're wrong. Maybe cite some other random nonsense now?