I leave Firefox open for months on end without problem and with several hundred of tabs open, multiple windows too. I do use a tab unloader, that unloads an inactive tab after a while. Its precisely because of this that other browsers are not suitable for me
Never had such an issue with Chrome, but man FF57 is my new default. SO FAST. I don't care if I need to restart it this thing is awesome.
I have exactly the same problem as the one you replied to.
It seems like some resources never get cleaned up, so if I in the span of a day open 100 tabs and close them then I will not end up with much higher memory usage than initially.
I have investigated this with about:memory and while not seeing something conclusive I did sometimes see domains taking up memory which were not loaded in any tab (ghost windows) or high amounts of memory used for "media".
I will try disabling the handful of addons I use beside uBlock Origin which is too essential to disable.
That said, I don't know if Quantum fixes the specific memory leaks you have, adds (back?) the extension hooks you miss, or adds the reporting you're looking for.
Even if it's the extension fault, why they aren't sandboxed properly, or even why there eisn't basic reporting about the offenders boggles my mind. Maybe it's because of the API... I find it hard to believe it isn't possible to retrofit some of that on the current design to be honest.
And now, because they couldn't handle it, we're getting extensions with crippled power, that are very (very) far away from feature parity with the old ones.
I wasn't happy before, and I'm not happy now, albeit for different reason.
The fact that I'm using Firefox of course means I'm not thinking too much of other browsers. The fact an extension in chrome can't add a frigging sidebar is a personal pet peeve of mine.
I remember when Firefox was the lightweight alternative to Internet Explorer 6...