The problem I think we all have on this thread when we talk about what driver line ups teams should have is that, as motor racing fans, we look at it from driver talent. The teams do not. Drivers do have to have a certain amount of talent but they also have to have great PR.
Sponsors know who Jenson Button, Kimi Raikkonen and Felipe Massa are. They've seen them in countless adverts and they have a mass following. If sponsors are going to put money in that's what they want. The guy doing the deal doesn't want to go back to their board of directors to say they've invested 50 million quid into something but it's OK because they can use Alex Lynn as the face of their product. They'd lose their jobs.
We only have 3 race winners who have made their debut this decade and only 2 of them have really broken into the Illuminati of top drivers. Ricciardo and Verstappen have the distinct advantage though of driving for a team which is it's own main sponsor, however the secret of their own success is actually the X Factor root. Just like in all those talent shows they have a back story. Ricciardo was the young Aussie who was following in the footsteps of Mark Webber in order to try and do what his 'mentor' could not by beating Vettel. Max Verstappen was the son of an F1 driver who is the youngest man to do everything ever. To be honest Verstappen is the Tony Blair of F1, I've never seen such a professional PR marketing push to get him in a top drive. Even from team Hamilton.
So the secret for the likes of Vandoorne, Rowland, Ocon and Co to getting a good drive is to be in the media, maybe with a sob story. Maybe lose a finger or something or have a relative that dies. I am joking but it is going that way.
Meanwhile the F1 Illuminati will make hay whilst the sun shines. They aren't invincible. Webber went a few years ago and Massa may go now but the rest will be around fora while yet.
Sorry. Rant. Prob needed it's own topic.