Our dog is crated when we leave the home only. When he was a puppy we planned to have him sleep there as well, but after about 3 months of no one in the house sleeping because he would screech all night, we gave up on that. Funny enough, he always goes in his crate to nap (voluntarily), and when he sees us getting ready to leave he will proactively run in there and wait for the door to be closed. He also likes to go in there when he is sick. I really do think he feels it's a safe space, but he is a very human-focused/velcro-y breed and if we are home likes to be with us.
In hindsight I do wish that we had been able to train him to be happy in there when we were home, but the combination of the horrible noises and lack of sleep was too much for us.