I can’t see it making much difference if shotguns moved to section 1 anyway those that are dedicated shot gun shooters will comply and just carry on with their sport why have two certificates when one would cover all firearms.
As for the argument on good reason join a clay pigeon club or a syndicate game shoot pest control on local farms might even encourage people to actually go out shooting.
very naive view on the impact, as others have said it would have a big impact on the sport and the industry, gun shops would likely close, you will likely get little for any guns you can no longer justify and the cost of all shooting would significantly increase, given the shops that remain would still have the same overheads but far fewer sales and likely less customers.