I've seen websites do just that. But why analytics would be more important to you than readership itself ?

In that case, you probably don't have to respect GDPR, as personal or household activities are exempted from its scope [1].

In any case, I would recommend looking up how to make sure your users' privacy is respected, it's always nice to make sure that, should their data be leaked, people are safe.

[1]: https://www.fff-legal.com/the-household-exemption-in-gdpr/

> Block my website for European visitors?

Under a strict interpretation of the law, yes.* (GDPR does apply to blogs, even if they're private) In practice removing analytics for EU visitors would probably be enough.

* Note that the physical location of the data won't matter for you because you are located in the US and are the data processor.