It is really a shame that basic functionality like this isn't built into more browsers and we have to rely on extensions to fill the gaps just to keep memory usage under control for tab-a-holics like myself. :(
chrome://discards/ has some advanced options (in Chromium-based browsers).
Funnily enough, Google mentions The Great Suspender as inspiration for this feature in the August 2015 changelog: https://developers.google.com/web/updates/2015/09/tab-discar...
> We actually had a great chat with the author of the Great Suspender extension while developing tab discarding and they're glad to see us natively tackling this problem in ways that are more efficient than an extension might be able to, such as losing the state of your user inactions.
I still sometimes use extensions like Great Suspender to give more control over the process (e.g. to suspend more aggressively on RAM-constrained machines or where the user uses a lot of tabs).
Since this news came out I have switched to "Auto Tab Discard".
The way I see it, extension developers get to come up with innovative new features first, and then the first-party vendors like Apple, Google, and Microsoft take note and eventually do just that: Integrate it into their own products.
For example: The Great Suspender → Sleeping Tabs [experimental] (Microsoft/Edge); Flux → Night Shift (Apple/iOS); Growl → macOS Notifications (Apple/macOS); Swype → iOS Built-in Keyboard (Apple/iOS); etc
Edit: Fix formatting.