That doesn't mean the other means wrap snap. It just means in order to truly install via snap, you should remove the same package installed via other means before
That seems to be a doc issue. It certainly did not install a snap when I just tested this, and the certpot python package it installs explicitly checks to see whether it is running in a snap or not, which would make no sense if running it outside wasn't an option.
> If you have any Certbot packages installed using an OS package manager like apt, dnf, or yum, you should remove them before installing the Certbot snap to ensure that when you run the command certbot the snap is used rather than the installation from your OS package manager.