I don't think it's just a skill thing; multibooting is more surface for "interesting" bugs and annoyances as you force interactions between systems that weren't designed to work together. Sure, you might know how to fix Windows overwriting the bootloader for the nth time, but it's still a hassle. Yes, you know how to get the UEFI settings the way you want them, but if you were single-booting the system would have done it for you. I get that it's not that bad once you're used to it, but there is a cost to these things.