The only people who are going to have more control post Brexit are the politicians and large companies. One of the good things about the EU is the ability to impose taxes right across the region so that big companies can't easily escape them. The burden of tax urgently needs to shift from individuals to companies and the only radical way to do this is to impose an EU wide turnover tax. This tax needs to be variable so that companies that do something useful would pay a low rate and companies that are seen to rip people off pay a much higher rate.
Another problem with the EU is the dislocation of people from the elite rulers, the parliament - the nearest normal people get to having a say - seen as largely sidelined and useless. Imagine then if there was a mechanism that allowed EU citizens to vote on the rate of turnover tax applied to the often cartel-like actions of some companies. Energy companies act like cartels, for instance, then people could vote to hit them with a much higher turnover tax. The same for finance companies that charge sky-high interest rates. The list is endless...
My own experience already suggests that UK companies are shit-scared of being reported to EU institutions but happily laugh off threats of complaints to UK ombudsmen. Imagine how they would react to the threat of a higher turnover tax if they are caught ripping off people. The use of a turnover tax is important because it is the one area where clever accountants can't fiddle the actual figures, unlike off-shoring profits or balancing them against loans from areas of low taxation.
Imagine how people would feel towards the EU bureaucracy if they said there would be a 5-10 percent reduction in income tax, the revenue to be replaced by the turnover tax. Individual countries would still be able to change the income tax rates back, bringing in all that extra revenue, but it would be political suicide to do so.