Best practice? 200PNG vs 6kx6k Atlas

Hello, I have a bunch of animations separated frame (512x512 - 20KB) by frame (>200 PNG per animation). Do you think I should pack them in a big PNG image (6144x6144 - 36MB) or keep them on separated files?

It has to be PNG because is main character with no background.

Placing them into a spritesheet is definitely the way to go. This link has a couple of pretty good insights into the reason why to choose a spritesheet over just singular sprites.