> Is this increasing complexity in the Web layout world worth it? Anyone who wants to use this is going to drop support for older browsers (and, in so doing, older machines that can't run newer OSes and newer browsers).

If you’ve been at this for a while, it’s important to remember that browsers update a lot faster than they used to. Anchor positioning came out last year, for example, and all of the major browsers support it by now. Very old devices are a problem but security is purging those out faster than used to be the case.

We also have better tools for progressive adoption since you can easily query for things like CSS feature support. In this demo, they didn’t implement fallbacks but in most real sites you’d have something like a basic grid layout which is perfectly serviceable for the fraction of users on old Firefox releases.