Well, I did close the door to keep my then puppy confined.
We had a fantastic routine for toilet training/play/sleep. She’s the 5th golden retriever I’ve had in my life and the only one I’ve used a crate with (the breeder had introduced crates, a lot of her dogs go off for show, so she had crates in the rooms the puppies are in from day one for them to go in and out of as they please, by the time she came to us at 12 weeks, she was used to short periods in a crate, saw the one we had for her and jumped in happily).
We thought we would give it a go this time and it’s been great. She’s now a very happy 2 year old and we no longer use one, unless in the car or on holiday.
Do you think she was screaming and crying and clawing to get out or something? She went in the crate, the door was closed, she went to sleep.
I didn’t want her getting out when she wasn’t supervised.
I didn’t want her wandering the house at night when she wasn’t supervised. I don’t allow dogs in bedrooms.
Crates really help some dogs feel calm and safe. It really helped with training mine.
ETA - my toddler likes her nursery, but they keep the doors locked so she can’t wander out. Just because you shut a cage door, it doesn’t mean the animal is trapped and is hating every second. You just don’t want them wandering out when they haven’t got your full attention.