To answer the last first, if I knew that, I wouldn't be writing on this forum, I'd be rehearsing my Nobel Peace Prize speech in front of the mirror and perusing the Mercedes S-Class catalogue.
The big difference is that the Netherlands (with apologies to my Loyalist countrymen, William III notwithstanding) does not, and has never been a part of the UK, which, through the vagaries of history has been chopped into two bits, one of which bits belongs to the UK, the other not, and with a substantial portion of the population overall thinking that this doesn't make sense and having shed much blood over it. This has, in my opinion, resulted in a unique situation, which is not really comparable with the situation with continental Europe. The last land border with the Netherlands disappeared at the end of the Würm Glaciation 15,000 years ago, as opposed to the one with the EU that sprang up on the island of Ireland in a somewhat faster than glacial speed. Given the history of our island, this situation is not curable by pat (if you'll excuse the expression) solutions.
I realise that you regard the EU as the devil incarnate, and, yes, they can be pernickety about their single market rules, but this was never in doubt, and it was predictable that Brexit would cause problems, but Boris, it seems, has learned from Admiral Farragut in the American Civil War ("Damn the torpedoes! Full steam ahead!"). Brian above is right, it takes two to tango, but what happens when an apparently suitable tango has been concluded, the band has packed up and, slightly sozzled, is half-way out the door on the way home, when one of the dancers drags his partner back and wants to do it all again to a music score that the band hasn't even seen, never mind rehearsed?
I agree with you that, for the sake of my countrymen, both North and South, the EU should give a bit, but, putting aside, if you can, your hatred of all things EU, given the creatures with whom they are dealing, can you honestly blame them for hesitating to do so?