I actually enjoyed ad personalization when it first started. I got shown ads for things that were actually interesting to me, video games hardware etc, but at this point it resembles what cable TV ads were when I stopped watching TV: car commercials, prescription drugs, baby and feminine products (am not parent, am not female). So now they just spying your behavior to learn the best way to trick you into buying crap you don't need and don't supply any sort of reach around.
The reason I hate ad personalization is because they flat out lie about what you're into. I hate crypo with a passion and shortly after I joined shitter they sold a package which said that I just looooved cryptocurrency and got nothing but the most cancerous crypo ads for the next year.