I don't doubt that the amount of social (and other) media coverage that The Hundred is getting with its fancy outfits (dubiously sponsored by fast food) will have made an impact upon younger people. However, whereas the likes of Kwik Cricket, All Stars etc are not unnecessarily challenging the fundamentals of the domestic game.
Indeed, those initiatives actually address the most important aspect - the lack of participation in the sport. Although plastic bats and coloured stumps may not be purist, there's no conflict (especially as the white ball game is itself very colourful).
The Hundred is based on the fundamental falsehood that the county game is somehow 'irrelevant'. If there has been any decline in crowds, it is because the ECB has messed around with schedules (the T20 Blast in particular, although it still pulls in crowds) and has foolishly encouraged the building of larger stadiums - which can only be filled by the occasional international match.
If the ECB had been more sensible in not encouraging unsustainable building projects by counties, allowed the scheduling of red/white ball tournaments, then there would be no need for The Hundred. Of course, that would mean that we still have 18 county teams - and we know that this is deemed 'too many' by those with vested interests in certain counties...