I would agree that simply sitting in front of a PC, not having done any real flying at all, is not going to be terribly helpful.
One needs to slot oneself somewhat into the "protocol" of flying and flight training, and then a sim can be very useful.
But if someone is looking at making their PPL easier and done in fewer hours (in the min 45 if possible) there is no better way then to find a
mentor, who takes you through the basics of planning a flight and then flying then plan for real. I've done a little bit of that and it seems to have worked well, with the chap having passed his ground exams before he even did much flying, and he will probably do his PPL in 45hrs which is itself a rarity. Just doing a PPL in 45 hours represents a saving of £ thousands over the average time/cost of a PPL. And a mentor can also get across some "airmanship" stuff e.g. looking inside the tanks before going flying
Actually flying a plane is really easy. Any monkey can fly a plane. It is all the other stuff (like landings) which takes the time. And some of the more subtle stuff which is IME poorly taught in the PPL e.g. trimming for the desired airspeed in all phases of flight is hard to learn from a sim because of its unrealistic pitch behaviour.
A sim with decent scenery can increase the enjoyment of flight training too. Early on, there is much emphasis on flying circuits, which most people find simply exhausting. At times, the training just seems to go on and on, with "tech" planes, missing instructors, cancelled lessons due to weather. But with a sim, one can do as much enroute flying as one wants, as early as one wants to do it. It could just help keep someone in the pipeline.