I don’t want to do anything else with these particular fields, just display them.
I’m asking both with regards to page load speed (eg number of database queries) and also to try to prevent some of the 504 crashes my site has been having recently when I am editing pages. (The crashes began when my husband rebuilt our AWS server in order to upgrade php for the upcoming Woocommerce php change requirement; we found that changing from php 7.4 to 8.1 helped matters but has not fixed issues and so I am now looking at trying to revise/check all of my coding.)
If you use the_field() on a field with no value then is simply will not output anything at all. There’s no need to check the field unless there is something else that is dependent on the value, for example a container element.