Does anybody build a website from scratch?

Yes, a lot of people create WSs from scratch w/o any other use of frameworks. It's no common, but it depends on the job itself.
If you wan to build more sophisticated things WSs, eventually you will rely on frameworks, even if you're a very competent developer, That's because you don't want to "reinvent the wheel", sort of speaking.
The other side, like "why learning html/js/css, when I can just use a platform like Wix?". Same thing, eventually, if you want more complex things you have to put your hands on the dirt, and knowing html5/js is always a plus.