When we talk about the UK's new found ability to diverge from the EU we need to ask who it benefits.

Most international businesses will want to keep us aligned - they want to continue to trading in the EU and having two sets of regulations to comply with just increases their costs. So they won't be in favour.

And if the UK does to choose to diverge it "doing so could lead to it losing the benefits of the trade agreement, and tariffs being reimposed, for example" as @SamuelMarcLowe explains in this excellent article: https://www.theguardian.com/politics/commentisfree/2020/dec/27/britain-trade-deal-eu-arguments-brexit-renegotiation
.

It's also worth keeping in mind the reason the EU can keep changing and advancing its regulatory standards is because not only is doing so for 27 countries but the 'Brussels effect' means these often become international gold-standards.

Who will the UK be writing its new rules for apart from domestic companies? Does it really think it can create a regulatory regime which could compete with the EU or the US? That seems fanciful to me.