The benefit to the deal is that without the deal, there would be no free trade with the countries the UK does the majority of its free trade with. In compariso

The benefit to the deal is that without the deal, there would be no free trade with the countries the UK does the majority of its free trade with. In comparison to remaining, the overall decision to leave whilst putting the deal in place ensure that UK [i] decoupled from a political project it had already negotiated an arms-length relationship with [ii] satisfied the sort of person enraged by seeing Polish shops that we could start denying Polish people visas should we wish to do so, whilst net migration is actually expected to continue at similar levels to before and we now face similar mostly theoretical restrictions on our own ability to live in EU countries and [iii] negotiated a slightly larger share of a fish quota, a political priority which has seen significantly more lucrative industries take the hit instead. We also have more ability to not follow EU law or product/service guidelines, but whether that's a benefit or not depends on which person you ask who's affected by which regulation