I'm probably not alone here in being a longtime Linux user who started using a Macbook after the Apple Silicon transition, late 2022.
On Windows and Linux, inserting an em-dash is a laborious alt-code process. But on MacOS with an Apple keyboard, the `option` key acts like a tertiary shift, so an `–` em dash is just <option><->.
I didn't start using em-dashes (typing -- is just second nature to me and I'm still on Linux most of the time) when I got a Macbook, but I imagine some people in my shoes did.
On Linux, you can set up a Compose key, after which an em-dash is compose, three hyphens (Macintosh: shift-option-hyphen), and an en-dash is compose, two hyphens, period (Macintosh: option-hyphen). Also, a left (resp. right) single (resp. double) quote is compose, less-than (resp. greater-than), typewriter single (resp. double) quote. That’s how I enter them.
You can also (alternatively or at the same time) set up a “Level 3 shift” aka “Alternate Characters Key” aka AltGr, which gets you quotes with one of the English International layouts or quotes as well as dashes with an English Macintosh layout.