I might not agree with you completely on what can be done to improve things in karting, but I will agree with you that the situation is pretty messed up.
And you made the right point; there was such a laser focus by the industry on the top-level they overlooked the base for a long time. I understand that when the economy nose-dived in 2008, the high-$$$ racers was the only recession-proof segment of the sport that karting could rely on to keep afloat, because everything below it was decimated. (And even then, the national series still took a big hit.) That was ten years ago, and a lot of decisions made by the industry since then didn’t seem to take to into consideration how it would effect the sport at the grassroots.
Sure the Briggs 206 has helped, but look beyond it and things aren’t all rosy. In some cases the 206 hasn’t so much brought growth but managed to save some clubs that would otherwise have gone extinct.