safari tab group sidebar - only groups "hot," not tabs themselves. Why not?

I have several tab groups in Safari: work, AWS, technical questions, finance, ...

I have the left sidebar open. I generally have 2 or 3 of the groups expanded, such that the individual tabs are exposed.

The Tab Groups are "hot" - click on them, and the top tab bar changes to that group, as expected.

The individual tabs are NOT - click on them, and nothing happens.

This is frustrating. Who cares if I can see something that's not actionable?

It surely would be nice if these individual tab listings were live, alongside the tab groups. Click on one, and its parent tab group is selected along with the tab itself.

Heck, even if the tab group is active, you have to click on the tab itself to use a particular tab, and NOT the listing in the left sidebar. That's a bit different - and unexpected - and disappointing - from historical behavior where bookmarks or tabs were listed on the left sidebar and you could click on them.

It appears tab groups is like a mutation - a new feature always tends to break an old, useful function.

Am I missing a feature, or is Mac OS/Safari??