Why does linux eat up all the RAM?

Question

linux

Hello, I'm running arch linux on my home PC. When the system is uptime for more than 10 days, all the RAM is eaten up along with the swap and I can’t fix it either, unless a reboot helps.
Bitcoind, chromium, firefox, kdevelop, virtualbox, telegram-desktop, ktorrent always work from software. Desktop Plasma.
RAM installed 12gb ddr3, swap partition 10gb. I also use systemd-swap for compression.
It is not possible to reset the swap using the swapoff --all command.
Over time, the entire system goes into swap and the OS slows down.
What could be the problem?

Answer 1

What does
?

Answer 2

Find the hero of the occasion through htop

Answer 3

First, everything is in order with memory .
The clue lies in the sentence
The most eaters are virtualbox, chromium, firefox.
All applications ask for virtual memory, which is often more than physical memory. At a certain stage, swap starts to be used, which slows down the work.
Solution: run fewer applications at the same time and open fewer browser tabs.
Or buy more memory.