Formula 1 has morphed to the point that I find it very hard to give a flying you know what about it.
I know it isn't pc to say, but one of the things that first attracted me to the sport was the danger. I first attended races in 1962, and the first three circuits I went to were Spa, Rouen, and Nurburgring, all of which, I suspect, would cause today's drivers to soil their fireproof underwear if they were told they would have to compete on them as they were then. The element of danger was still sufficiently great in the early 70s that, when I got home from fighting for Queen and country in Viet Nam, I was still amazed that the drivers would take such chances. With today's Tilke tracks, with runoff areas big enough to land an A380 on, the element of danger has been so greatly reduced that, IMO, you face more danger on your daily commute.
Furthermore, it seems to me that today, the WDC is essentially meaningless, as the result is 99% down to the car. If you swapped the drivers of Mercedes with those of Williams, I am willing to bet that Hamilton and Bottas wouldn't be close to getting wins. I remember when Chapman introduced the monocoque chassis and Clark trounced everyone, the other teams didn't appreciate the advance. They said, essentially, that "Ah, well, Clark can win in anything". That has totally gone as well.
I believe that, the only was for F1 to survive is to make the drivers MUCH more important to the results. If that requires a semi-spec series, so be it. The sport existed, and, indeed, thrived without the manufacturers. It could easily do so again. What it needs are heroes, not drivers that are, essentially, inconsequential to the results as, IMO, they are today.