Does it though? Has this ever really satisfied you … that you get to login and then circle your mouse for a few minutes while you wait for things to kick off.
Na, all or nothing please I don’t want to be teased by an is-it-isn’t-it experience I want my boot to take its time, let me know what’s going on and when it’s all there let me enjoy a responsive experience.
It’s just a cheap trick and it probably doesn’t matter as much as they think it does.
Whenever a user interactable element will be ready in <~100ms, you can display it as ready now, because it is faster than the reaction speed of a human, which makes all interactions with the software faster, smoother and more responsive than if I used a loading indicator. It's a free win.
Whenever you know in advance you need to display something to the user and need to load/process something that takes much longer than 100ms, you can load in the background while displaying whatever needs to be displayed and if the time spent on the screen is slower than the loading time then the next interaction will be instant (common case), if the user is faster on the screen you can still go to a loading screen, but the time it is on screen for would still be much much shorter.
Knowing things in advance is not a cheap trick. I’m not talking about a well structured boot. I’m talking about the far more common approach of just showing a moving mouse pointer and a few icons and “pretending” the computer is ready to use, a notion that is quickly disabused as soon as you try to get to work. Then even, you will her no way to know when it “is” actually ready.
On my C64 I'd start loading a game from cassette tape before dinner so I could play it afterwards.
I had to type the games source code in from a magazine for my acorn electron.
Punched tape[0]: Hold my beer
The Altair launched with a cassette tape interface anyway.
In my mental model, the technology distinction is more between single user and multi-user systems. And arguably that is more a a software differentiator than a hardware difference.
On my 9 track tape I would be lucky if the thing loaded and was ready to use 72 hours later [1].
When is the last time you cold booted a modern Apple Macbook for example?... Minutes is an absolute exaggeration.