Unfortunately, while written with the best intentions, there are a few (a lot?) of guides around which are very much outdated or not really correct.
Think about guides requiring you to install git and clone the whole repository, just for the
certbot-auto script Probably there wasn’t another way back then, but nowadays there is…
Also, sometimes other unnecessary workarounds are used, because some features didn’t exsist yet.
So with outdated guides you risk doing things not really the correct way.