if you open a terminal window on mac with any kind of display 1080p, 4k whatever with any resolution you will still get a 80x24 terminal by default. Which is the whole purpose of `git log`. Using it on a terminal / ssh session / whatever.

I use ~80 cols terminal because everything is designed to fit in 80 anyway. More than that and it's just whitespace.

People use VMs, print stuff on paper, have 10'' laptops, etc.

The reason for this is that Git patches are meant to be exchanged over email. Historically email has a line limitation of 80 characters. You are supposed to use less than that to allow insertion of quoting characters in the first columns in replies.

Your email client is supposed to fix this restriction in a completely transparent way. There are a few standards for that, and you can bet every client supports all of them.

Uhm, no, that is not the reality we live in. Things like format=flowed exist, but I would not say that "all" clients support that. For example Apple Mail lately got an obsession for quoted printable encoding with very long lines.