Your BIOS, can’t do anything besides “fast boot” setting, which is not recommended if you need your keyboard on boot… (on most motherboard it will skip some devices initialization).
Grub loading (waiting, actually), can change that by setting the timeout value in its config, here you probably have it set to 3 seconds or you pushed enter after 3 seconds.
Desktop loading basically… you can still gain some time by removing programs/services loading on boot
Indeed that’s huge, and this is the kernel loading, that’s right.
From the other loading times I can see you’re on SSD.
Give your /etc/mkinitcpio.conf file content, maybe there is something weird in there.
Also give proper system information if you want support. Give the most details about everything related (file system, partitions, and so on).