There are advantages and disadvantages to exterior egg collection.
One of the biggest disadvantages is weather proofing and predator access.
Hinges/door(s) can leak and it's another entry to coop that needs to be secured against predators.
Advantages are cleaner shoes when gathering eggs and easier to clean and change nest bedding.
I've got the best of both worlds as my nest access is outside coop but still inside shed, tho I still have looped latches on doors in case anything gets inside shed.
See My Coop page.