Technically SoCal is right.
Although of course the student can "fly" - i.e. operate the controls, they couldn't land the aeroplane I suspect due to insurance requirements for one thing. The second thing is the PPL is responsible for the entire flight so better be confident with their mates flying!
I think it is good experience to fly with a qualified pilot supervising. I have been safety pilot in the USA numerous times for people about to take their IR checkride and wanting some proper practice in IMC. It is good for me too, free hours and getting experience from the RHS (I'm not an instructor yet).
I took my dad up the other day and let him fly the entire flight, bar the take-off and landing. The last plane he flew was a RN glider about 50 years ago, and which he managed to crash
But he did well, and really it is pretty easy to keep an aeroplane straight and level (well, in his case within +/- 300'
)