> Tighter integration than UK
Sounds like it could be a solution for the UK as well, which begs the question: why wasn’t a similar proposal worked out with the uk?
The UK left and wasn't even able to make proper deals for exiting the EU, their own Brexit caught them by surprise and it was total chaos for a long time. They could now try to get closer integration with the EU but there doesn't seem to be much will for it in the UK.
Because the UK wanted out, not in. You can work out solutions only when you are looking to work out solutions.