Our spaniel is 8 and came to us as a very fraught, very stressed 12 month old who'd been badly treated. We crate trained her on the advice of a specialist we brought in, never closed the door, never used it as a punishment, never raised our voices at her, never touched or moved it etc and 7 years on she loves it. The door is always open and the DC know to leave her alone once she's in it. As others have said, some dogs need their own space that's just theirs. Our dog is happier and calmer for having it.
Our new puppy is 10 weeks and, again, his crate is always open, it's just a space that's his. No stress, no locking away, nothing but a calm, quiet space. Even at 10 weeks once the 8 year old takes herself off to bed he follows her and trots off into his crate. They're side by side but covered in warm blankets, and in the winter they have little microwave heat pads under their beds to keep them snug. The puppy often goes and has ten minutes in his crate throughout the day. The spaniel takes herself in less frequently but when the DC's friend visit or things get too hectic she heads off and has a little peace.
We have two DC who often have noisy friends over, we have cats and we often have guests. It's a busy house and for our dogs, their crates are simply a little bedroom of their own.