I've been betrayed early enough and often enough to take monthly backups of my profile and export tab lists as text files. Just in case.
All of you going 'well that's not my use case' don't have to get it, you just have to shut up and let us do our thing. Yours is the same aggravating attitude as 'so what if the computer reboots to forcibly update?' Listen: go to whatever physical space you've carefully organized, dump all that shit onto the floor, and then pick it back up piece by piece to make it right again. How you feel doing that is how we feel several times a month.
Mozilla has proudly advertised testing how Firefox handles hundreds of tabs.
There's not some upper limit. A computer remembering a hundred things has not been impressive since the days of drum memory. Open tabs in a restored session are barely more than bookmarks.
Sessions aren't restored by coincidence. They're meant to be persistent - that's why there's a mature and stress-tested feature to keep them persistent.
Go whine at someone expecting their hammer to work on a thousand nails. They don't write on the packaging that it'll work that long! It's only designed for a couple dozen nails, and then you throw it out.
Tabs also need to be closed occasionally for major updates. You know how I know that? Because it happens regularly enough that you're here whining about it.
You're welcome to keep banging your head against that wall, but if you publically whine about how it hurts your forehead, people are gonna tell you its your own fault. And they're right.
The browser needs to be closed. The tabs persist... because they're saved, and then restored. You know how I know that? Because I've been doing it for TWENTY FUCKING YEARS.
When that goes wrong, it's the software fucking up. Same as deleting your bookmarks, forgetting all your passwords, or erasing your whole profile. All of which I've also dealt with, and if someone told me I'm stupid for calling that an error, I'd slap them.
I'm not fighting anything except your ignorant horseshit comments - the software works how I want. Only you whiners think it's not supposed to. Like Mozilla made it work this way by accident. Fell ass-backwards onto increasingly reliable session restore options.
When that goes wrong, it’s the software fucking up. Same as deleting your bookmarks, forgetting all your passwords, or erasing your whole profile. All of which I’ve also dealt with, and if someone told me I’m stupid for calling that an error, I’d slap them.