Where does the money go? Paying over a million staff isn’t cheap and is probably the largest single component. Buildings, drugs, research, IT, food, equipment, admin (lower than comparable systems), vehicle maintenance, data analysis and probably a lot more I can’t think of.
Just because you don’t comprehend the scale of things doesn’t mean the money is all wasted. This isn’t a dig at you, it is normal to not understand large systems, but don’t take your information from sources like the Daily Mail or The Express.
Yes there are inefficiencies such as in procurement not being allowed to just buy from a local vendor at a much lower price, but overall it is not that wasteful.
If you wonder where billions go now just wait until we have privatised systems and it is costing much much more for far far less.