I have been on admissions committees and there is of course the possibility in your mind that students who did not submit scores probably had bad ones. I certainly prefer having scores. But when tests are optional, plenty people will also just want to save the $50 or whatever it costs to take the thing. Particularly from poorer families. So you can't be sure and hate to reject a super candidate on this reason alone. Also there's always some people in admissions who are adamantly anti-test anyway.

They do look deeper into the high school's reputation and individual course grades to make up the missing info that the test would have provided.

It’s probably like a lot of companies that offer remote work: if you have demonstrated already you are world class, they’ll make exceptions.

FWIW, all the people I know who went to “world class” universities did all the “optional” things.