Per the silly AI answer on Google, not really? You can enable it on Firefox easily enough. Everywhere else? Good luck.

Even in Firefox, the dream of meaningful styles across sites is largely dead, I thought.

> Per the silly AI answer on Google, not really?

There are people who read that?

> Everywhere else? Good luck.

Same as with alternate stylesheets or a reasonable line of death. For all the annoying things Mozilla does, Firefox is still a great browser and for some measures the only shop in town.

> meaningful styles across sites

You can also modify the browser chrome with it, and I think UBlock Origin uses it for modifying the page. Also some settings are exposed via a UI, so also lawmen not knowing about user.css might still use the user (agent) stylesheet.