Isn't "crime, done with the involvement of a firearm" also often more harshly punished than the plain crime itself? If a burglar is targeting empty houses, this would give them a strong incentive to not bring a firearm, just in case they get caught.

As the saying goes, only break one law at a time!

Yes burglary with weapons is called robbery and is treated as a more serious crime with a higher punishments in a lot of jurisdiction