An app for Mac called MenuBarX, which allows for little browser windows to be displayed as drop-down tabs from within the menu bar of macOS. I can choose the size, as well as customize a few other things (I have mine set to iPhone 8 in terms of screen size). I also have it set to launch a series of tabs upon lunching the MenuBarX app - which (currently) are: 1Feed, this blog (olry.co), and Read.write.as. And that's all I need on there for now. A lot better than a bunch of dedicated tabs on Firefox, I think. Plus, I will not (accidentally) close them if I ever close out of Firefox for whatever reason. And I don't have to bother reopening each site each time, either - I just launch the MBX app, and there are the (tiny) tabs waiting for me :)
Also, I just found out what my niece is having (boy or girl), but she has not shared with everyone yet, so I will keep it to myself for the time being.