They used to be discoverable with mnemonics (underlined letters) but those have been dead nearly thirty years…
these still exist on windows though? you just hold alt
Only works for like 20% of the menus though. I remember alt shortcuts reliably being on every single menu in early Windows (95? ME? XP?)
loading story #48416211
loading story #48413338
GTK (and QT I do believe) also support this on GNU/Linux.
I wouldn't say they're dead, just more hidden (e.g. GTK4 only shows them when you hold Alt). AFAIK most toolkits still support them, but app developers also have to actually define them.