Yes, some features were also implemented in Opera Chromium but many others weren't.

"That was a different product" isn't exactly true. It was different code-base, yes, but is essentially portrayed as the same product. Most features were carried over into the current rendition, and I used the tab grouping feature a lot in the old versions. I was sad to see it go, and several years later, I still find myself wanting it back because it worked very well for me.

They changed it before, they can change it again.

They didn't but,of course, they can change it in the future

Opera used to have this feature, and it was great.

It was back in Presto era, so we are talking about a different product. And I remember many people complaining about it.

@maybemark Workspaces are Opera approach to tabs grouping and i don't expect them to change it in a near future.

They changed it before, they can change it again.

Opera used to have this feature, and it was great. It was way better than the current Workspaces, because you could quickly and easily make tab group "folders" on-the-fly. They never said why it went away, but if it wasn't because it infringed on a patent or something, they should definitely bring it back. Circa 2014 https://ww.youtube.com/watch?v=VWpJvg8icmM