i give zero F about whatever is in my /usr, /var/lib and /opt folders. what are websites gonna steal, debian binaries and libraries? all my important stuff ar

i give zero F about whatever is in my /usr, /var/lib and /opt folders. what are websites gonna steal, debian binaries and libraries? all my important stuff are in my home directory, which is owned (read+write) by me, the same user running the browser.