I'd like to block access to websites on my Pixel 3 android device. The parental settings leave much to be desired and apps like BlockSite don't work across all browsers. (In this case - it doesn't work in firefox)

Here's what I tried so far

adb pull /system/etc/hosts ~/Documents/android/hosts

I edited the hosts file and got it ready to be transferred back.

adb push ~/Documents/android/hosts /system/hosts

This gave me error message: adb: error: failed to copy '/Users/[username]/Documents/android/hosts' to '/system/hosts': remote couldn't create file: Read-only file system

Per this post and this post, I tried a few other options.

I tried to use these commands

adb root
adb disable-verity
adb reboot
adb root
adb remount

This gave me error message: adbd cannot run as root in production builds and when I tried adb disable-verity it said: verity cannot be disabled/enabled - USER build.

I tried to use this command

adp remount

This gave me error: Not running as root. Try "adb root" first.

I downloaded an emulator and tried this command on my device

mount -o rw,remount /system
mount -o ro,remount /system

Similarly, this was unsuccessful