There’s also the fact that the EU has had mission creep that Britain may not have anticipated or signed on for.
Britain joined the EEC, which was a trading arrangement in 1973. The EEC morphed into the far more political EU in the early 1990’s.
So, for Britain to want a trade association with Europe, but not to be politically subservient, just goes back to their original intent.
The EU like the UN is simply the INTERNATIONALIZATION of the WEALTH REDISTRIBUTION scheme the Marxist left (but I repeat myself!) has tried to impose within various individual nations -- INCLUDING HERE -- AND HAS ALWAYS FAILED! BREXIT IS THE BEGINNING OF THE END OF THIS ONE! Despite efforts by former East German communist youth leader Merkel (she's still a commie, for those who haven't noticed!) and her ilk, OTHER DOMINOES WILL FALL!