Ah, I misunderstood what you were referring to. Now that I understand, I'm less surprised. For some reason I was thinking File I/O.
The Early 2020 MacBook Air is a joke from a CPU/Graphics perspective - even compared to other Intel Macs.
I still think something's wrong with your computer, as I have worked with multiple of that model and they weren't nearly this bad (even accounting for screen recording) - perhaps your cooling is worse?
It’s more pronounced while recording but that’s the idea.