In order not to be ultimately governed by an unelected EU, as opposed to a domestic government that isn't elected by a majority in the absence of proportional representation. But hey, the EU isn't telling people what to do and they can always just protest for extra handouts to pay for the spiralling costs of netflix subscriptions and Deliveroo drops.
Far from the people advocating a no deal being those who wouldn't have to actually suffer the consequences, a great deal of them are people who are clueless as to the consequences they are likely to face, or believe the spin that those consequences will not arise, and buy into the bluster. In power, of course those with means (as with bankers) will always win out of adversity, further increasing inequality in the process.
South Africa responded to sanctions by domestically substituting imports. They even built Mercedes-Benz cars there because it was essential that Madam got to drive a new Mercedes whenever she wanted one. Mozzarella cheese was made locally to ensure you could still get an authentic tasting pizza, and foreign brand fashions were replicated meticulously. Those with means would hardly know day-to-day that anything was wrong - until they tried to travel abroad and take their money out. All but the wealthiest effectively became economically locked in behind their own borders, but it was a pretty comfortable home arrest for them.
I did also say "to some extent"