When it comes to technology, The UK loves selling their own businesses rather than selling goods and growing into large tech companies these days. Just look at Imagination Technologies which was sold to a chinese private equity firm [0] and Apple is now producing their own graphics chips. Brexit just made the price tag cheaper for them and Softbank.
ARM is beyond saving at this point when NVIDIA and other companies may be bidding for it. What a lost opportunity for the state of UK technology companies even when they keep comparing it to the crown jewels being sold off. [1]
[0] https://www.bbc.co.uk/news/business-41369376
[1] https://www.bbc.co.uk/news/technology-53637463