The regions of the UK that voted for Brexit will probably be hit the hardest because a deregulated environment for technology companies will not benefit them. The loss of the single market and JIT manufacturing will, most certainly, lead to the closures of manufacturing sites. We could also imagine the downfall of some industries in the UK (aeronautics for example).
The eye-watering spending plan will require cash, a lot of it, and the COVID + Hard Brexit that's currently looming could very well prevent it from happening. The government has not been great so far at following up on their promises.
The EU was scapegoat that the government and tabloids used for a lot of issues that were mostly national (including the infamous immigration laws). Even after leaving the EU, the blame game is still in full play; never is anyone taking responsibilities for their actions, it's always the others' fault.