First, it should be stated, if you cannot physically vote in-person and there is no trustworthy person to drop your ballot off for you, then you should VOTE BY MAIL.
However, if you are an able-bodied and healthy voter, it is better to vote in-person to prevent unnecessary backlog at the USPS. The federal post office was already overloaded by changes due to Covid-19. On top of that, federal cutbacks in funding are looming. IF you do not want your ballot sitting in a sad, little corner of the postal room on election day, take your lunch break and drop it off in person. Make sure that it is postmarked. It is the proof you need that it was sent before the cutoff date.