>where privatisation has mostly worked in the UK is the telecommunications market. Here the networks are in private hands, but the providers are forced to offer somewhat equitable access to their competitors, e.g. by sharing masts, poles and underground ducts.

Not strictly true, currently the Govt is subsidising infrastructure providers to the tune of £3000 to £4000 per household for every one that has fibre to the property (FTTP).

So a company like this one https://countybroadband.co.uk/ needs to get about 30 households signed up, they have 1 year to get the cables laid to their greenbox street furniture, and then then run fibre from village to village until it ends up back in London, probably telehouse.

So its costing about £90k per greenbox, and depending on where on the run you are, you might see a bit of a lag if you are at the end of the run in places like north norfolk, but if you live in a village somewhere in essex, ie closer to the main routing points in the UK, then the lags will be less noticeable.
This also ignores cloudfare type data centres which cache the most popular content and locate it close to your door.

But there's a govt subsidy here going to businesses, in this case infrastructure providers for home users.

Now if you take this place https://en.wikipedia.org/wiki/Cwm_Dyli its got fibre which it had to pay for and cost £200,000 a few years ago when it was strung up the poles. But its also benefited everyone in the area who didnt have to put their hand in their pocket, but the fibre is somewhat exposed on the telegraph poles imo.

There is actually alot of fibre already in use in the UK, because fibre doesnt really change, so the improvements in fibre come from lower costs and improved compression ratios by detecting the traffic type and then compressing it, which requires a level of oversight on everyone's internet traffic going in and out of the country. Goonhilly has been doing some of this sort of algo compression/traffic detection testing in the past. https://thefalmouthconvention.com/record-2/field-trip-report...

Rail companies push up the costs, much of it through clever accounting, setting up leasing companies for rolling stock, separate companies for man power etc etc. You'll be surprised how many foreign companies have a slice of the british railways. If you are fed up with the state of the rail services, beat up on the foreign countries and companies that have a slice of the pie.

Roads, builders all submit tenders, the unwritten rule (for all types of building work including schools, hospitals in the UK) is if you dont want the work, submit a super expensive tender, those that want the work price competitively.

The main advantage of privatisation, is you get new ideas being tried out more quickly than with socially owned or governmentally owned entities. In other words it brings diversity to the table, instead of conformity.

Legislation already brings conformity in many ways, but this is still after people but typically businesses have been consulted on for a govt white paper.

It also gives govt the ability to say its not my fault when something messes up, so if you really want to beat up on the govt, get everything taken back into state control, then beat up on the govt. If the govt is smart, it will push responsibility's onto other people who feel they have the chutzpah to run a multi million/billion utility company, in the words of L'Oréal "because they are worth it".