When I right click on a tab in Firefox, I can reopen it in a container. The containers (at first glance) seem to be limited to Personal, Work, Banking, Shopping, and Facebook (which is probably there because I have Facebook container installed). In settings I can modify the container tabs available. (And turn the feature on or off, but it's already on because of Facebook container.)
Is that what that is? It looks a lot like the example you linked. Firefox 123.0, but it's been there for quite a while.
It's in their DNA. They completely missed the internet boat when it first took off in the early 2000s and played catch-up for years thereafter. You would think they would have learned and not made the same mistakes again that you have in your list, but nope. Maybe they were too busy fighting Linux.