Welcome to the club!
And yes, it really makes a difference. And, there are even extra extensions for TST: I use a color tabs extenaion for it as welm as an extension that lets me export a tab tree as markdown for use in my notes or to batch "bookmark" them before closing them.
When you do, feel free to find the "cheat code" to disable the top tab bar, it makes it a whole lot less noisy to me at least.
The second reason why yyyy-MM-dd is the correct way to write days (beside being sortable by default) is because even Americans doesn't have any similar format that it can be confused with.
I learned this in my first half year as a programmer I think, somewhere well over a decade back and so far it seems that guy was right.
How can you use anything that doesn't support Tree Style Tabs?
Or do you use Orion or something?
I expect you have tried to search for it in Firefox, but have you tried sideloading it somehow?
As far as I know Firefox supports a superset of the APIs that Chrome support, so it should be a possible?