I think it depends where you live as to how long your lessons need to be.
Back in 1963...!! when I learned to drive, I had to travel to King's Lynn which, although 20 miles away, that was where the nearest driving schools & the test centre was.
Therefore, I had to get to KL on the bus, or occasionally my Dad took me, then I had a 1 hour lesson at a time. (I had 20 hours at £1 each) (I was an apprentice earning £2:50 per week).
In 1989, & in 1997, when our own DC were learning, & very recently, when our DGD took her lesson & test, they were all picked up from home, it would have taken at least an hour to get to & from the city that they were to take their tests.
So they had plenty of on road general practice to & fro, plus an hour in the city, & thus needing 2 hours in total.