This is interesting because the basic arguement matches a recent Telegraph opinion piece - and it’s both correct and naive. It’s correct because the only way Brexit could have worked economically speaking was to use it to deregulate, lower business taxes, shrink the state etc. It’s naive because the majority of U.K. voters - especially those who voted for Brexit - don’t want that. They actually want a European social model - high spending on health, education, defence, etc. And the only way you can have that in today’s difficult geopolitical world (given our geographical position on the European continent) is to be part of the vast, pan-continental single market and customs union that exists to deliver the European social model as far as is possible. This is why the Labour Party, in government, will eventually begin the process of joining the European single market and customs union. The only other option is to follow the Brexiteer vision of a much smaller state - and a large majority do not want that. As the recent Telegraph piece pointed out, these are the only two choices that do not lead to inevitable economic decline.