Though Brexit is definitely part of it, this is the whole Tory austerity programme from the Tory/Libdem coalition onwards.
Tory means Tory.
Their repeated claim that their party is good for the economy, unlike "magic money tree looney lefty liberals", is about as believable as the scrawny kid who used to come in the pub and tell everyone "he could kill a tiger with one punch, and he'd got SAS training off of his dad, who was also a ninja".
If we genuinely used that to reinvested in our population to fill jobs we might be looking at a different situation. Brexit was a mistake but we could have done something with it.
We have no job training, huge unemployment yet it's far easier to import people from the third world to keep house prices high for the upper class to profit.
The only way we could have made something of Brexit is to remove work, financial & environment protections to turn us into an exploitable tax haven.
It's partially being done hence the shit in rivers and removal of banker bonuses. But it won't help 99% of people. Only the richest 1% who'll fuck off to the EU for citizenship and benefits while paying fuck all tax via tax loopholes in this country.
Depends on what you mean by making it work. Growing gdp yes. That's probably the only way.
But a lot of other things could have been done. Build a shitload of houses and forces businesses to do more on the job training and move to low employment areas could have had a huge huge impact. But this absolutely would have had to be tied to low immigration to have worked.
It would have decreased gdp or stopped it growing as much but people would have more jobs, more discretionary income and better living situations. Personally I think that's better than increasing GDP.