that their internet connection isn't good enough
a person who wants to work remotely but doesn't figure out how to have a good internet connection, then they are not a good fit for remote work. If a person decides to travel to a location where internet connection is not good on the day of the interview, you can imagine what he/she will do when it's a regular work day.
Somebody shows up for a remote job and doesn't have a good internet connection is too big of a hiring risk to even both continuing the interview.