Changes are too little. Many big brands do not want to be involved in F1, many like Hass or Williams will struggle financially another year.
F1 is not 'flat out all the way' anymore, it was when Rene Arnoux was racing. What F1 drivers do those days is managing pace and tyres. Stupid FIA policy introduced after they abolished refuelling to 'improve racing'. Not to mention it generates a lot of waste on track, and off track. Not too good for environment.
Challenge? Easy: MotoGP
Much better close fast racing. All what you want plus no politics or cheating by riders or officials.
Best racing in cars you have in Austrialian V8 Supercars those days. Have a look, couple days ago:
Endurance racing is also much better, but hard to watch due long races.
There is much more, but not covered on TV and not promoted so hard as F1.
F1 paddock are saying for years now, F2 races are often more interesting to watch than F1.
Nothing is perfect, but when officials are involved in results of championship every racing fan should feel cheated.