I've been watching F1 since about 1982 at the young age of 13. Well reading actually because in North America it wasn't live on TV and you had to wait for the monthly Car & Driver to get a race report.
I just have to say that this weekend's race sucked.
F1 is not Endurance racing. It is supposed to be Cars on the bleeding edge of Technology that will grenade themselves to pieces if you look at them wrong or complete one more lap than the race distance.
The three engine rule is not saving any money at all. In fact I would suggest it is costing a lot more.
The supreme focus on Aerodynamics also has very little application in the real world.
I say for 2021 the regs should be very simple. One engine per race weekend or a penalty. Points are only counted for say 17 out of 20/21 races (in the 80's I think you counted only your Top 10 out of 16), cut the downforce by at least 50% (probably making the cars prettier as a result), and cut the minimum weight significantly - call it 550KG to allow for hybrid systems. The weight limit was 500KG in 1987 - none of this 2018 728kg nonsense. With todays material science and engineering cars should be able to be quite safe at that weight.
Limit the Fuel allowed in a race and just bring it down over time to control power and incent Manufacturers to work on fuel saving solutions which will benefit the industry.
Cap boost pressure to limit HP, limit exotic materials, specify engine configuration - I would suggest 2.0 L 4 cyclinders again for Road Applicability. Don't limit Fuel flow.
Sorry for the rant - it needed to be said.