My £0.02 worth....
The Navy should "defend the realm" along with the other armed forces as appropriate. Only after that is assured should we debate whether "force projection" is necessary, and if we decide it is, then you have to spend accordingly.
Problem is, the requirements change faster than the snails pace of procurement, so it's never right. Add inter-service bickering and top-heavy management (more admirals than ships?) and the results aren't good. Doing stuff on the cheap rarely works well, and when it does, it's usually down to the skill and bloody-mindedness of the guys at the pointy end somehow dragging it out of the fire.
Thing is none of our PPE graduate politicians ever seem to have bothered to study any history......