Let me just start out by clarifying that I mean are they essential with regards to fielding works entries into F1?
As engine suppliers I do see them as being essential because the teams do need engines to power their cars for one. The other is that the engine is the most relevant component in a F1 car for the manufacturers.
WhiteBlue has been insistent that the auto manufacturers should be encouraged to field actual teams into the sport. I disagree with that as there is nothing that has shown they are needed for the sport to survive. If anything, there is little relevance to their R&D to be had from F1, since the focus is no longer on engines. Audi said as much when they said they had no interest in participating in F1 as the extreme focus on aerodynamics benefits them not in the least. Further they had said the inability to develop engines in any meaningful manner made the whole thing pointless when one considers how little benefit there is to be had.
Given that the auto manufacturers do not have the level of autonomy that private entries have into F1, they are subject to the whims of their corporate boards.
I don't see why anyone would want teams that can be gone at the drop of the hat if there is any sort of economic recession, or if the company decides to move in a different direction.
What are your thoughts?