This x1000. However, not using JS is also not necessary. There are valid reasons to use JS even in a simple personal site.
The way I see it, keeping it as simple as possible is most important. Much of the time that means HTML & CSS only, maybe however, you want to have tabs at the top (for example). Is this possible to do with HTML & CSS? Yes. Is it simpler to do with JS. Also yes, and it doesn't take hardly any to do.
There are certainly valid reasons to use JS, and it can greatly enhance a site if done right - interactive examples in a blogpost is one of my goto examples where JS can enhance things a lot. Same with comment systems that allow you to see a real-time rendering of what you are writting.
This x1000. However, not using JS is also not necessary. There are valid reasons to use JS even in a simple personal site.
The way I see it, keeping it as simple as possible is most important. Much of the time that means HTML & CSS only, maybe however, you want to have tabs at the top (for example). Is this possible to do with HTML & CSS? Yes. Is it simpler to do with JS. Also yes, and it doesn't take hardly any to do.