Should I complain about employees at Subway closing an hour early?

You could always ask the owner and you'd probably be told that owing to pandemic strain on all restaurants and staffs that they're currently having to operate at different hours. Life just isn't normal right now so you can't expect things to be as they were before the various shutdowns and unemployment payouts made it very difficult for restaurants to operate. 

You should bring the incident to the franchise owner's attention.  You should also find a better place to get subs like a Jimmy John's, Jersey Mike's, Quizno's, Blimpie's, Firehouse, etc...

https://en.wikipedia.org/wiki/List_of_submarine_sa...

A lot of shops are being told to close early at the minute, due to Covid laws. A lot of them aren't running under normal times at the minute, they're running under Covid times. 

You couldn't go to another Subway™?

i would complain about it

Sean Dalt! Where have you BEEN! I missed you! And bless you, you've even put in your trademark whine about the employees being on their phones!

Ah, vintage Sean Dalt!

If they do it all the the time then yes, otherwise no

No, you should get on with your life and deal with it.

There could have been any number of reasons for their closing early.

There could have been a small fire, an electrical fault, a sick member of staff, a sudden bereavement - anything.

This sort of thing happens.

Be a grown-up and don't give such things a second thought.

Stores are closing 1 hour early due to covid. The Best Buy I go to closes at 7 pm because of covid.

It could also be closing earlier because of a curfew.  

Put your concerns in Google review and or Yelp.