I know there are a handful of idiots who will get a dog despite working 8-6 Monday to Friday and then at weekends the kids have clubs so ... but come on.
Unfortunately, over the fifteen years or so that span a dogs life, things can dramatically change and sometimes rehoming a dog is the best thing you can do for you and for the dog. I don’t mean that to sound flippant by the way.
I’ve known dogs rehomed because of disability, death, dramatic change in circumstances (like having to move to rented accommodation) - it’s almost always because of stress and adding to it by making the person feel like the worst person in the world doesn’t help!
And sometimes a dog just isn’t suited to one person or to one family and it’s OK to be honest about that too.
I’m sure half the posts about regretting dogs would be deleted in a second if they were about regretting kids!