I have the kennel recommendation discussion with at least 80% of my customers. With each one, I reiterate the dangers of wireframe kennels and urge them to spend the money on a decent and safe kennel. After all, you've spent money to obtain your dog, feed it, keep it healthy, and train it.
TLDR;
A motivated dog trying to escape can bend the wires, breaking them from their welds, and in the process, get their jaws trapped (as in this video of a dog needing to be rescued) or collars caught on the wires, leading to strangulation.
While no kennel is 100% free of risk to a highly motivated dog, except perhaps the High Anxiety Crate from Impact, there are much better options. I recommend only Ruffland or Impact kennels.
The Stakes
Here are a few of examples of what I'm talking about. Recently, on a Facebook group I'm part of, a member posted a video of her dog escaping from his wireframe kennel. Thankfully, the dog was not injured. However, he quite easily could have been. If the welds at the bottom of the wire door had broken, this dog would likely not have survived this. You can see part of the way through where he has his head out and is starting to panic.
Another user replying to this discussion related how her dog did the same thing but was not so lucky. Her dog passed away the same day it was injured.
Below right is another example of a wireframe crate that impaled a dog's mouth after it tried to put its snout through an opening in an effort to open the door.
My Recommendations
As safer kennel alternatives, I recommend only two: Ruffland Kennels* and Impact Dog Crates. Ruffland kennels are one-piece plastic roto-molded kennels that are safe, sanitary, and secure. If your dog sometimes has accidents in the kennel - the Ruffland is the best option. Virtually all the dogs that participate in my board and train use these kennels and they are ideal for the home. The Impact kennel is much more expensive but it is also one of the safest kennels you can get for a dog that has anxiety - particularly their High Anxiety model.
Due to the enclosed nature of both of these kennels, they make perfect den environments when it's darker out. As den animals, dogs feel safe and secure in their own dens. Wireframe kennels offer no such environment unless you cover them with something - which then puts you at a risk of your dog pulling in and chewing on the cover - possibly ingesting something that may harm him.
Note
If you do end up buying a Ruffland Kennel and have a dog that requires a Medium to X-Large kennel, I recommend a single door option only and strongly recommend buying the Metal Door Liner.
Note that Ruffland is currently backordered 16 weeks on all new purchases. Also, note that I am a Ruffland Dealer, but I only use my dealer status to get small discounts on kennels I buy for my business. I do not resell them.
Alternatives
Those two are not the only kennel manufacturers out there. There are numerous number of premium kennel manufacturers, including Gunner Kennels and Lucky Duck. I do not have personal experience with the latter, but I did own a Gunner Kennel for a while. The Gunner Kennels are perfect for transporting your dog to and from the field in your vehicle. The double wall construction makes it the safest in a crash, but also means that they are heavier, larger on the outside, with tight interiors. There is often not enough room inside the kennel for your dog to live in comfortably for the rest of their life.
I would avoid the standard 2 piece plastic kennels you can buy at common big box stores, or airline style kennels. The plastic is thinner and there are more openings for a dog to get his teeth on. It is not uncommon for dogs to just chew their way through these - sometimes ingesting plastic that gets lodged in their intestinal tract - requiring surgery to remove.
This picture is of a dog injured by escaping through just a plastic kennel.