Obviously back when F1 was free-to-air in most global television markets more people probably watched it in aggregate, but viewership started moving to pay-per-view back in the Mosley and Bernie era.
IMO, in terms of "general public interest" in the sport, F1 has never been more popular than it is now and that is, again IMO, directly attributable to Liberty embracing social media whereas Bernie was very much against it (even though drivers and teams wanted it).
And yes, that brings a lot of the drawbacks of social media, as well, but the teams are financially stable and so are more and more circuits and overall, the sport seems healthier with more manufacturers wanting to join.