I think lower open-wheeled series today are a lot closer to F1 than they were in the 90s, though. Karting does appear to be dominated by drivers backed by kart manufacturers, ex-F1 drivers (Jos Verstappen is probably 1/3rd of the reason Max Verstappen is dominating everything; he is very good at setting up karts and getting the best parts, people, etc), while lower Formula series are a little more open. You still need a good team, of course.
I think that also might be a reason why Formula Ford is fading away fast; Formula Abarth, Renault ALPS or NEC are entry-level formula cars, but with far more appeal and F1-likeness than Formula Ford.
I think Jos Verstappen has an ideal plan for Max, who is 16; another year in karts while doing a few races in a Formula Renault 2.0 championship or something similar, and gradually moving on to bigger series per year. Giedo van der Garde tried to do that, but got stuck in GP2 for a couple of years. Sirotkin might want to get some more experience before entering F1 for his performance’s sake, but if his backers are hellbent on getting him in F1 next year, he’s bound to end up feeling like Alguersuari or Tuero.
And I have to agree with wsrgo, Chilton didn’t get the best results in his junior formula career. I don’t consider him to be a ‘terrible pay driver’, but I do feel his money compromises his poor results in GP2 and before.