They can't keep going with the current setup due to how changing demographics are producing increased demands on the NHS. People using the service are much older, with more complicated diseases, then ever envisioned when we designed the systems.
Beaurocracy is causing inefficiencies due to too much red tape. We spent £5.1 billion on "costs of harm" in the year 2023/24 which is quite a large amount of the £160 billion total budget. Running total of outstanding compensation claims was recently £83 billion. We need a way to fix the processes to prevent these clinical failures or find some way to cap the amount of compensation claimed.
Additionally the use of short term contractors is hemmoraging money. Often the management will give IT contracts to large firms like accenture who fail to deliver semi-regularly while charging a premium. NHS administrators frequently use the big names because they are recognisable instead of interrogating which company is actually best placed to deliver.
I'd personally be happy with looking more closely about how other European countries handle healthcare. They seem to spend less for better outcomes, while ensuring that everyone who needs medical treatment receives it. If it can save lives we shouldn't be too ideological.
Edit: In Scotland health is devolved, we get higher levels of funding per capita due to the Barnett Formula, and lastly income tax is higher to provide more money to the NHS. Outcomes are actually worse here than in England due to mismanagement. Seems like an example of more funding not being a silver bullet.