There's an extension[1] now that restores the functionality, but the removal is exactly why I'm hesitant to try a new tab organizational tool: the loss of the last one was workflow breaking enough to break trust.
I still use it successfully, but there are a few annoyances with drag and drop in the panorama view. It isn't as nice as when it was integrated unfortunately.
[1] https://github.com/projectdelphai/panorama-tab-groups