I concur with deacdixieboy regarding the lack of known/marketable drivers these days. In my mind, none of the younger (30 years or younger) drivers are particularly interesting, at least to me. So many of the well known, charismatic and popular drivers left the sport within about a 4 year window of time between 2014-2018 (such as Tony Stewart, Dale Junior, Jeff Gordon, Carl Edwards, Matt Kenseth to name a few) leaving a huge black hole. There are a few holdovers from those years (the Busch brothers, Brad Keselowski, Kevin Harvick, Martin Truex, Jr.), but nowhere near as popular, and certainly not enough to pick up the slack.
I was a huge (and long suffering) Dale Junior fan who made it a point to watch every race if at all possible. The Sunday afternoon race was my "leave Daddy alone" time. Since Junior's retirement in 2017, I could not care less who wins or loses (as long as that assclown Joey Logano doesn't win -- I actively root against him).
I am probably typical of many fans. The only race I have actively watched this season was the Martinsville race, because I was there in person. However, the product on the track was so bad, I'm not sure I want to go back. Sponsorship is declining heavily due to diminishing viewership. I'm not sure what NASCAR can do to right the ship.