Sewage has always been pouring into rivers since Bazalgette built the first one; so it's more correct to say that the sewage system hasn't been completely re-built to match modern expectations to avoid doing that. Why? Cos it'd cost literally hundreds of billions across the entire sewage system because many parts filter rain water, and when it rains too hard then it overflows into the rivers and people don't want to pay for redesigning and rebuilding the entire system in one go as their bills going up hugely, so it's being done incrementally over decades by replacing old stuff that needs replacing anyway. Much like most of Europe, except that it's simply not a political issue elseware relative to other issues; for instance the Germans are mass strip mining the dirtiest sort of coal.
With respect to "Decrepit railways"; refer to this:-
https://www.theguardian.com/public-leaders-network/2016/may/04/privatised-nationalised-electrified-guide-uk-railways-network-rail
Why is it struggling?
Network Rail inherited a lot of problems from its predecessor and needed to invest heavily in improvements. To do this it was borrowing money, backed by government guarantees so the state would have to pay back its loans if it defaulted.
Who was Network Rail's predecessor? Oh, that would have been Railtrack. So why did Railtrack have huge maintenance issues? Because they had inherited that from British Rail when the government owned it. Why did they have maintenance issues? Given a choice of maintaining railways or spending it on the NHS to buy votes, where do you think the government chose to spend money? Yeah. Hence the existing maintenance backlog.
People have a tendency to engage in rose tinted glasses when looking back; not everything was actually better.
most expensive energy costs
Led by a deliberate choice demanded by the public to move power generation from a triad of coal, nuclear and gas (offering security as a failure in one area could be countered by the other two sectors) to generating all power via gas. Sorry, generating everything from renewables backed up by gas. Except that renewables don't tend to work as well as people are encouraged to think, and gas is required for cooking, heating and power generation. And as idiots support running down producing our own energy needs in favour of wanting to buy it in from abroad where we don't have any real control over the prices then it's inevitable that they will then complain it's expensive because there are no forms of power generation they'll actually accept. For instance, German electricity is cheaper. But that's because they mass stripmine lignite (the dirtiest and most polluting form of coal with the lowest power output) and burn that to get their power prices down. Are you willing to do that? No? Well, that's why our prices are higher.
Slow growth, falling living standards
Um. Slow growth and falling living standards are because after the nationalised industries went kaput investment money was shoved into housing because "it's safe as bricks and mortar" and we're the generation having to pay more for necessities (like power; see above) as a result and so have less disposable income and are worse off as a result.
We've also got more of a habit of complaining, because absent of shared experiences like our cities being carpet bombed by our neighbours we tend to (from the POV of the nearly departed generations who lived through that) lack a certain perspective and complain more about smaller issues that are in most case fairly self inflicted like the higher energy costs. (ok, the Russians exploited our idiotic policies for their own benefit, but creating situations where they could do that is on us)
So as a list of emotive keywords; top marks. However, your notably evading any form of rational fact based response, or critical thinking. ;)