@SunnyInGrimsby
I must challenge your assertion that if people didn't breed dogs the supply of dogs would 'dry up'. This simply isn't true. I have a rescue charity and work with countless rescues here and abroad who deal daily with an avalanche of abandoned puppies; the best thing that can happen to them in this unkind world is for them to be put down.
I think we can all agree that the best scenario is that people everywhere stop breeding puppies for whom no homes are readily available and instead breed dogs sensibly and with proper regard for their welfare. This has been the line taken in Britain for the last 30-odd years, such that now many of the puppies sold here are bred in puppy farms abroad and imported. This strikes me as something of an own goal.
I did once calculate that about 20k dogs were euthanised in rescues and shelters in the UK each year. This is obviously too many (though some of those will have been for issues concerning health or temperament). However, it needs to be kept in mind that there are somewhere between 8 and 9 million dogs in the UK, and to keep that population stable (assuming an average life expectancy of 12 years) will take about 700k puppies (and imported dogs) a year. Perhaps we want that population of dogs to fall, but even if we assume that 20% of pet owners aren't fit to own a dog and shouldn't be allowed to have another, that's still a lot of new dogs every year.
A rescue dog from Romania is not what every pet owner needs, wants or can cope with. I live in a fairly rural area and within the last year or two I've known of two dogs brought here from abroad who have gone AWOL, being nervous of people and other dogs. One was found and returned to its new owner after several days roaming the countryside and crossing fairly busy roads; the other was never seen again. I know someone who has two, and one cannot be let off lead.
I'm not saying in any way that rescuing from abroad is wrong (I have financially supported this at times). What I am saying is that if we stop breeding puppies in Britain, we will lose lines of dogs of known ancestry, with moderately predictable temperaments, coats and so on. And for the sake of dogs in Romania, Spain, Greece and God knows where else, we need to be persuading owners there to treat their dogs better, breed them more thoughtfully, and take more responsibility for them. If we do that successfully, the supply of unwanted dogs from those countries will, thankfully, dry up.