The only thing that shows is that it's more difficult for EU based companies to trade in post-Brexit Britain, which was already obvious. Companies are leaving the UK as it's less attractive. That's not really onshoring so much as filling a gap in the market created by companies leaving.
All that means is less competition and a more isolationist market, which most people agree is not a good thing for consumers. Brits will lose their jobs with EU companies and move to work at British companies, which just equals loss of earnings and uncertainty for them, also not great. And that's assuming best case smooth transition and picking up the slack in production left behind.
Personally I don't give a shit where a given company I buy from is based, I want the best quality goods provided at the lowest cost.