Another point about slow flight is that it provides experience in flying the aircraft at the back of the drag curve, when counter-intuitive effects need demonstration. (you need more power to fly more slowly straight and level). Landing itself is a slow flight activity.
So many PPLs have lost touch with these skills, I find PPLs uneasy at slowing down to 50-55 kts for a performance landing in a 152 for example. The pernicious effect is to develop PPLs who approach far too fast and wonder why their wonderplane floats for ever, or alternatively say 'It needs flying on to the runway'. Where is the lost art of holding off? Cessna 172 drivers flying approaches at 75-80 kts when 60 would be more appropriate.