"Remember when we owned that company? But then the powers-that-be decided that privatising would give us cheaper prices, and subsequently opened the industry up to multiple players when they realised that wasn't working."
I think you've introduced an extra step there. Competition was introduced alongside privatisation - first with Mercury (owned by C&W, also a privatised former goverment monopoly) and then other operators applied for licences. Later, the license requirements were eased and now anyone can set up a telco.
TPTB were right about one thing though - prices are far cheaper than they were and amongst the lowest in Europe. That's one of the reasons for takeovers and mergers and all that stuff - owners are trying to get out because low prices means there's not much profit in UK telecoms - notice that there's not so much eagerness to sell mobile operators elsewhere in Europe.