The primary reason I care about analytics is to see if posts are getting read, which on the surface (and in some ways) is for reasons of vanity, but is actually about writer-reader engagement. I'm genuinely interested in what my readers resonate with, because I want to give them more of that. The "that" could be topical, tonal, length, who knows. It helps me hone my material specifically for my readers. Ultimately, I could write about a dozen different things in two dozen different ways. Obviously, I do what I like, but I refine it to resonate with my audience.
In this sense, analytics are kind of a way for me to get to know my audience. With blogs that had high engagement, analytics gave me a sort of fuzzy character description of who my readers were. As with above, I got to see what they liked, but also when they liked it. Were they reading first thing in the morning? Were they lunch time readers? Were they late at night readers. This helped me choose (or feel better about) posting at certain times. Of course, all of this was fuzzy intel, but I found it really helped me engage with my readership more actively.
You might get no monetary value from having 12 people read the site or 12,000 but from a personal perspective it's nice to know what people want to read about from you, and so you can feel like the time you spent writing it was well spent, and adjust if you wish to things that are more popular.
IPs are useful in case of attack, but you could limit yourself to simply logging subnets. It's a little more aggressive block a subnet, or an entire ISP, but it seems like a good tradeoff.