Heard a detailed analysis of privatisation versus state ownership in relation to a couple of industries, on Radio 4 on a car journey. Upshot was that it didn't make much difference, in many ways!
My gut says privatise, and make it all British owned. Unfortunately that leads to operatives who have and use too much political leverage.
E.G.Train drivers do a low-skilled job . The requirement is 2 GCSEs, grade C. Only about 15-20% of the population doesn't achieve that.
So you can be well below average. Training can be 1 year, then you're qualified, earning about £60k pa.
That's all wrong - compare with many other jobs.
Any monopoly needs governing by a competent overseer which sets pay, terms and operational standards (hard!). If you do earn a grand a week and you go on strike, you lose pay and have to pay an admin fee plus a grand a week to employ someone to replace you.
I know that's not a "utility", but it's topical and close.
Same for buses, ports, roads, water, power, leccy, schools, NHS, emergency services, maybe others. Most of the Civil Service I guess.
Some like medics, schooling, needn't be exclusively state.