I'm a professional and power user (now 4K+ tabs opened).
I'm using Sidebery since 2020: with lateral tabs, grouping and panels, Sidebery changed my way of using the browser and it's great, organized and efficient.
Thank you so much!
P.s. Probably it's the main reason because I stay with Firefox.

Suggestion: in the years, it happened 2 or 3 times that it has lost the hierarchy of my tabs and flattened the list, so I've set Sidebery appropriate automatic snapshots and to avoid eventual bugs, if a version works without problems, I update Sidebery to a new release only after many weeks since it has been released.