Guess it all comes down to your needs. I had an 8-year-old dual-core i5 HP desktop computer that I wanted to replace. I only used it to run GIS software (for making maps) that isn't available on the Mac. Took a chance that it could be replaced with a new i7 six-core Mini with 64gb RAM. Didn't like the idea of using bootcamp, since then I wouldn't be able to use it as Mac during long compiles under Windows, so I installed Windows 10 under Parallels.
Works better than I ever hoped, the same software from my old Windows PC runs much, much faster and I have had zero problems in three months of heavy use (have spent more time in Windows than MacOS actually). So this has really been a perfect solution for me, although I can appreciate that it wouldn't be right for somebody that wants to play games or run software like video editors, etc.
I also have over $5000 of legacy 32-bit Mac software on a couple old Macs. But now I run it all on the new Mini in Mountain Lion and Sierra virtual machines. So, I've replaced three old computers with a single new one and everything runs much better than it did on the original machines.
Many years ago, I ran Windows 95 (?) under Virtual PC on my PowerBook G3 (the big, black curvy one). That worked, but it sure was slow and buggy. Later, I ran Windows XP in Parallels on my 2008 MacBook Pro. That was certainly better, but still pretty slow and buggy. Coming back to Parallels almost 10 years later now, I'm very impressed. Haven't had a single crash yet and I really like the integration with MacOS. So - for me - I'd say there isn't any reason to use bootcamp. But that's just me.
FWIW, the regular version of Parallels is limited to two CPU cores and 16gb of RAM, which is why I went with the pro version. I'm using two cores and 32gb RAM for Windows and don't seem to need any more than that for now.