Sure that work is going to happen but often what you see is multiple stylesheets loaded using the async hack which results in multiple style and layout calculations as the browser can coalesce them because it doesn’t know that they’re stylesheets or when they will arrive

The whole philosophy of critical styles philosophy being those about the fold is a mistake in my view

Far better to adopt approaches like those recommended by Andy Bell that dramatically reduces stylesheet size

And do critical styles “correctly” i.e. load those that are needed to render the initial page and load the ones that rely on interactions separately