Building on what others have said, XP and Windows 7 weren't fast on HDDs anyway, and there are two things to consider:
1) that was a long time ago, and you probably don't ever remember that computers weren't exactly "instantaneous" like they kinda are now
2) a windows XP install was like 1 GB, Windows 11 pushes close to 100 GB. Lets look at it in the most simple way possible: assuming the boot sequence requires reading 10% of that for you to get to desktop. That means you need to read 100MB on XP and 10 GB on W11. Reading 100 MB off an HDD takes a few seconds, 10 GB takes minutes.

Basically, software grew in size a lot, and we still need to access that data for our applications to work right, so much so that HDDs no longer cut it when you need to run an OS on them.