Its not Huawei's fault they have a virtual monopoly
I don't think there's a term in the English language for an "accidental monopoly". I'm pretty sure that Huawei is smart enough as a company to realize that having a monopoly on a technology isn't a good idea, there needs to be a vibrant ecosystem of competing products to grow the market, but owing to a complete lack of investment in R&D in this field by companies in the US they've been handed the entire business on a plate. I don't think this is the only case, just the most public. Look at all the products you see about you and ask yourself where they and their components were made. The chances are that most will be from China or an alternative Asian supplier.
I find it a bit ludicrious that the UK should be even debating this topic., Their electronics industry preceded the US by several decades, descending in to a mush of overpriced (and underperforming) custom military kit and small boutique operations like hi-fi amplifiers. There's obviously been pushback -- engineers like to make things, after all -- but by and large being an engineer in the UK during the 70s and 80s was a soul destroying activity as industry after industry fell to foreign competition (aided, especially after 1980, by government policy). Moving to the US you saw exactly the same forces at work but the US was starting from a much higher perch so was going to take longer to fall (our 1980s era happend post-2000).
I suggest that if you don't want 5G then just go without. We've got a bit of it in the US but the offerings and coverage are embarassing, they're just marketing fluff that underscores how badly we've been caught out.