Surprising indeed. Windows 10 boots quite quickly (don't know about Windows 11) but the boot of a fresh install of the latest version of Debian feels instantaneous. In a systemd container, it boots under 2 seconds even with a few extra services.
> but the boot of a fresh install of the latest version of Debian feels instantaneous.
Starting with latest iterations CentOS 7 and Debian 10, booting Linux is almost instantaneous. We have quite a few VMs, and after restarting one (i.e.: reboot <enter>), I just need to sip a little coffee to be able to SSH into a fully booted system.
On the other hand some of the higher end servers we have can fit a meaningful chat to the booting process (in fast boot mode, no less).
This means that most of the overhead is hardware initialization waits, IO and GRUB.
BTW, X11 is not modesetting 5 times on me. Maybe the first modeset you see is kernel's terminal modeset?