There is often a lot of traffic and commotion in a household and sometimes dogs just need to get away from it all. If they have a crate (or kennel) that they are use to, it provides an atmosphere where they can feel safe and secure. They can go to their safe place to escape situations that might be frightening or stressful, or even just to take a nap.
We were Dash's fourth home. I was relieved for him when I found out that he had always liked his crate. When there were big changes in his life, he always had his
own little shell that he could retreat to when he was nervous. (Turns out he's ALWAYS been a bit high strung, but his crate helps with that, too.) ;O)
A crate is especially good for rescue dogs (in my opinion). When I foster, I always try and crate train them if they have not had a crate of their own before. I want them to be able to take their "safe place" with them when they are adopted. It really helps with the transition from one home to another.
I start a foster dog's crate training by putting the dog's bed in front of the open crate in the same room that I am in most of the day. When I decide that they are not concerned about the crate being there, I put their bed inside the crate (again, with the door open). Once the dog is going in and out of the crate on their own, you know they are comfortable. Closing the door to the crate is sometimes a little scary for them so I do this at night with the crate next to my bed. Before long the dog is going into his crate at night as well as when I leave the house without any hesitation.
Depending on the personality, the foster might just learn by example like Walter did. ;O)
There are some situations that require crates. Being from Texas, evacuations come to mind. If you ever have to evacuate because of a hurricane, tornado, flood, etc., the shelters always require that pets have a crate. They will almost always have to turn down pets that don't.
There are many other situations where a crate can make things a lot easier. I have a friend who's dog learned how to open the condo door when they would leave for dinner. She would escape the room and eventually find her way via elevator down to the main floor! As entertaining as it was (after the fact, ha!) it is not a safe situation to find your dog in.
Staying in a hotel, an RV or camper, or just staying at a friend or family member's home can be much more pleasant with a dog who is use to a crate.
One year my son and his wife brought their two big dogs home for Christmas. Since we didn't know how the dogs would react to a little white dog running around, (I pictured a rabbit in their eyes) we up-sized Hermes' crate to "shark tank" and let him stay where he was more comfortable and out of reach of the other dogs. Once all three dogs got use to each other, Hermes was still able to get under his blanket in the crate and take a stress-free nap when he needed some alone time. ;O)
Some people don't like the idea of their dog being in a crate and they all have their reasons, but I truly believe (if it is not EVER used as a punishment) a dog loves having his own space to unwind and feel secure just like we do.
**If your dog has never used a crate before, you need to take some precautions. You should never just put your dog in a crate and then leave if they have never been in a crate. They could panic and injure themself trying to get out. As with all training, each dog is different so the training will vary accordingly. There are many posts on-line about crates and I encourage you to look at articles from advocates of both sides before deciding what is best for your dog.