To answer the question whether a dog stroller is a good idea, the circumstances and needs of the dog and the dog owner should be considered.
The most obvious consideration is the health and age of the dog. For dogs with health or mobility issues, or a dog recovering from surgery a stroller can provide a way to have the dog join their parent who is on their outside exercise routine. For those dogs certainly it would be better to ride in the stroller than stay at home.
If you are a long distance walker or runner, your dog may not be able keep up with your pace so a stroller gives them a chance to join you. Smaller dogs, especially the toy breeds may tire easily on long walks so a stroller will allow them to walk till they tire, and then go the rest of the way in a stroller.
People living in a densely populated area, may find a dog stroller useful on crowded streets. Likewise, when you are attending festivals, outdoor shows and markets, a pet stroller maybe the best way to have your dog accompany you for the entire day. They will have their safe space as you enjoy the outdoor activity.
There are shops where dogs are only welcome if they are being carried. A stroller means you can enter those shops and not have to carry the dog in your arms, giving you the freedom to shop with your hands free.
Nervous dogs often feel less anxiety when in their own stroller.
If you are fostering puppies and making visits to the vet with several puppies, a stroller is a good option for transporting them.
In conclusion, dog strollers can be a good idea for certain situations and some dogs. Assessing you dog's needs and your lifestyle will be the determining factors as to whether a dog stroller is a good choice.
View dog strollers here: https://getkennel.com/collections/strollers