I really don't understand why this exists. Tab grouping is such a minimal and intentional cognitive task. Why would I want to offload this to AI?

Using AI to let UIs suggest sensible defaults is, IMHO, one of the less appreciated ways that AI can improve our interaction with machines. As long as the models is local, fast, and the suggestion is not disruptive, there is very little to oppose these, even if the benefit is not realized by all audience.

I think we'll see many many more instances of this type of AI use in our everyday tools, including UIs of physical products.

Stop putting "AI" into my browser, put those resources into a better browser instead, kthxbai.

Can I stop having everything "suggested" at me?

I know what I'm doing with my computer, thanks. I don't need "suggestions" and "recommendations" shoved down my throat because tech literacy has slipped so far backwards.

That could be useful

A much simpler heuristic would be to simply group tabs automatically when the tab is opened by clicking a link, or by searching a phrase that appears on the previous tab. No AI needed.