I realized I didn't want to manage profiles, I just wanted separate containers by default. So that's why I use Temporary Containers. I don't maintain a "work profile" or "shopping profile", etc. When I need cookies or other data shared between tabs I will Ctrl + click to open a link in a new tab, with the same existing container.

Now, to organize tabs I use Tab Stash. I put things like 200+ YouTube music tabs in 1 group, 1-off projects in another, k8s stuff in another, job/career postings I need to complete in another, etc. Things that are temporary are shown under the default group at the top. This also allows me to keep most of my tabs "frozen" and out of memory/inactive while still keeping 400+ tabs open.

(Tab Stash is vertical tabs. Sidebery was the fastest, but Tab Stash has the grouping and inactive tab stuff I need)