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?)

They died when people stopped using native toolkits and started making everything an electron app.

Economics be damned, if you're going to make a native app, use the OS provided toolkits.

Hah, I was thinking 3.1…

Yeah I only used it a little bit so couldn't remember if it had the "hold alt to see shortcuts" thing

GTK (and QT I do believe) also support this on GNU/Linux.

I remember using TweakUI to enable "always show underline for shortcut key" because that genuinely felt like it should be a default for better usability.