Answer is, it depends.
If he is interested in a profession like Architect or medicine then he has no choice.
If he wants a degree with a wide variety of career choices then STEM subjects are the best choice and value, particularly ones that contain a significant maths component (physics, electrical engineering, civil engineering, chemistry, maths, computer science etc). With a degree like this you can go on to working in lots of different technical areas, IT, engineering, R&D, accountancy, law, because getting the degree "proves" you can handle the maths.
If he is not up to doing STEM (a lot of people struggle with the maths) then I would say probably better not to go to university and concentrate on something vocational. Trades (heating engineer, builder, electrician, plumber) are all in short supply at the moment and are well paid, but many require some level of maths.
I would think very hard about doing humanities, languages, social science etc.
I would also strive very hard to get to the university with the best reputation possible. Because it won't cost that much more than one of the lesser ones, and degrees from good institutions are valued much more highly by employers despite what a lot of people will tell you.