Don't worry, Colin. It won't be this bad every time, but it's always going to be worse than it was.
Also, do expect lots of photographs of the politicians, who advocated Brexit, going through customs and declaring it was all project fear because it is fine for their journey.
im actually confused, is this just Schengen-related given nothing else is really substantively supposed to change for UK passport holders until the end of transition...
Now imagine you're driving a truck crammed full of "just in time" supply chain goods
Sitting 55th place in the tailback waiting to clear customs
And getting bombarded with furious texts from customers who's businesses are going under because they cant meet orders
To be concrete: UK never was in Schengen, but of course could use Schengen rules applicable for EU visitors. When you voted leave, you voted for leaving this rules. So you have to wait as anybody else when travelling in the Schengen area.