Opera ditched their browser engine. They use chromium now.

I don’t get why people are so resistant to using bookmarks. This is literally their purpose.
This isn’t a hard problem. Nobody needs to keep 400 tabs open. You aren’t reading them all at the same time.

Bookmarks are synchronized, grouped by folders, and don’t disappear unless deleted.
You can open an entire folder with a couple taps. You can switch between tabs with a couple taps or a swipe on the toolbar.

Someone posted a list of features the other day that are being worked on and it included tab groups, planned for this year IIRC.