Many people who don’t know what they’re talking about in this thread. No, used memory does not include cached memory. You can confirm this trivially by running free -m and adding up the numbers (used + cached + free = total). Used memory can not be reclaimed until the process holding it frees it or dies. Not all cached memory can be reclaimed either, which is why the kernel reports an estimate of available memory. That’s the number that really matters, because aside from some edges cases that’s the number that determines whether you’re out of memory or not.

Anyway the fact that you can’t run Linux with 16GB is weird and indicates that some software you are using has a RAM leak (a Firefox extension perhaps?). Firefox will use memory if it’s there but it’s designed to cope with low memory as well, it just unloads tabs quicker so you have to reload often. There are also extensions that make tab unloading more aggressive, maybe that would help - especially if there’s memory pressure from other processes too.

Pano perhaps? It doesn’t show up at the cursor but you can search in it, the keyboard works the way you would expect and it auto inserts on selection.