Treat it like a personal blog maybe? Like Tumblr or a journal. Might help get over the mental hurdle of people not being present, and viewing it like your own private web page just for you. Posts also help it show up in all so eventually someone will see it.
I did try that, but found that it still remembered site info for accounts I was logged in until fully I closed everything related to the firefox browser. So containers has been easiest solution except for the process of manually creating and then deleting ones I didn't need anymore beyond the one session.
I had used Temporary Containers, but it hasn't been updated since February 8, 2021. Not actively monitored for security by Mozilla either so stopped using it. That addon was a perfect experience though for what I wanted.