I was wondering if your tool was displaying cache as usage, but I guess not. Not sure what you have running that’s consuming that much.

I mentioned this in another comment, but I’m currently running a simulation of a whole proxmox cluster with nodes, storage servers, switches and even a windows client machine active. I’m running that all on gnome with Firefox and discord open and this is my usage

$ free -h
               total        used        free      shared  buff/cache   available
Mem:            46Gi        16Gi       9.1Gi       168Mi        22Gi        30Gi
Swap:          3.8Gi          0B       3.8Gi

Of course discord is inside Firefox, so that helps, but still…