One feature of Brexit from the perspective of those who see political and economic benefits to remaining a member of the EU is that there is no safe, perpetual compromise position.
There are soft versions of Brexit in which almost all the economic benefits of membership are reaped [for example by remaining in the single market and customs union]. But once we leave it becomes much easier to take further steps away from the EU, and the UK’s economic trading relations, regulatory environment and even to an extent political rights become unethered and more subject to the ebbs and flows of domestic politics.
For Remainers, EU membership is an economic and constitutional anchor; anything short of this is casting off.
Some Leavers saw things exactly the other way round, of course.
They either feared, or manufactured fears of Good Ship UK Political and Social Norms being dragged by an ever more powerful EU polity, itself a changing entity with the potential for new members to accede. Membership of the euro, an EU army, EU wide budgets, funding for future bailouts; obligations to take some of those who migrate into the EU.
For these leavers, rightly or wrongly [in fact wrongly], Brexit was the anchor and continued membership was casting off.
This is at least part of the reason why the issue is so divisive and intractable.