The sealing of the filesystem can be disabled trivially, though, via a command line tool that Apple ships with MacOS that you run from recovery mode.

And then you can remount `/` as read-write, and create a new blessed snapshot with your changes made to it.

This doesn't actually delete the signed snapshot though, so the space consumed by `/System/Applications/Chess` still is consumed. I'm not sure if MacOS will allow deleting the final sealed snapshot for `/`. It might, I don't know that anyone is clamoring for it though.