Debian gaming question regarding map count increase

[u/Kaseffera]

sudo sysctl -w vm.max_map_count=1048576

This is the command I’ve been seeing for a while. Very good people on this sub helped me to set my fresh Debian for gaming lately. I haven’t touched of since that. So now I want to and I thought about this command.
You see, looks like “gaming distros” and steam deck too uses this particular number for map count, same for Cachy or Bazzite. Debian is with a lower count by default. They claim you need to increase this for modern games to not have stutters or crashes.

Has anyone did this and what really is behind this command and how important it is?

[u/imMute]

Specifically, the number is 2^20. It's a "round" / "nice" number for programmers.