Datensparsamkeit! There are more reasons to wanna to be in control of the data if your users instead of selling it off easily (e.g. the trust of your users). Additionally it can feel good to just know what happens instead of telling yourself: "I use google analytics like everybody else — that must be okay"
I actually develop my own solutions, there is no third-party analytics involved in my blog, the only "analytics" I do, is to keep track of which IP visits what resource, the only cookies that are set on my blog are session and chain IDs.
If you have the information available, on what the mentioned threshold is, please do share.
For the less than 10 visits a day my blog receives, of which 98% are bots, I'm not going to do a deep dive into GDPR policies.
In Europe, law doesn't work like in the US in the way that it's to be taken literally, but in the way that the law was intended - which is not to discriminate amateur blogs, but to enforce data protection amongst the big players, i.e. Facebook, YouTube, etc...
Therefore, I still stand by my original claim: For an amateur blog, don't crack your head over GDPR.
EDIT: Provided, of course, you don't use the tools of the big players, e.g. Google Analytics.
Not sure where I read it, but it was in the range of something around 10,000 per day/week/month.
Definitely not something to crack your head over, if you just want to host a personal blog (unless you're a celebrity?).
SOURCE: I self-host a personal blog in Germany, and had read up on it a year or two ago.