I have several hundred open on my M2 MBA and have no problem. Maybe it's because I use Brave? I don't know but have never had to think too much about it. I also don't have much RAM (either the base amount or up a little).
I do restart my browser once a month or so, if things ever feel less snappy than normal.
In Safari, tabs get small up to a point, then they are scrollable. Sure, there are duplicates but it's usually the homepage of HN or Twitter. I close those when encountered.
I do restart my browser once a month or so, if things ever feel less snappy than normal.