Sure, I am currently earning enough money to be able to afford messing up my books if I wanted to but it feels so wasteful. Feels so weird to purposely vandalize your own stuff. I prefer making notes in a separate medium and keeping my books clean.
I like being able to gift or sell my books to other people. Plus, I might want to re-read them and I really dislike having any annotations in them. I feel like it would stop me from having a "fresh read".
Thinking about my childhood, the vast majority of the books I read were from libraries. School books were also all lend from school. Sure, I also owned plenty of books myself but my parents would have been pretty pissed if I vandalized them as my siblings might want to read them.
For me books where always something to share not something to own. Never got the need to make them "my own".
Honestly, when people who take care of their things die, it's like an explosion of wealth. The things in my place range from the mid-19th century to today. If you let people pick through my shit and take something that looks cool, my death could result in 1000 smiles.
edit: I even take care of the things that I've made. They're no doubt mine, but some of those things will make someone else just as happy as they've made me.