My biggest problem with Modern Formula 1 is the advancements in Tyre technology. It has completely changed the way the sport works and not for the better. It's similar to how the advancements in both golf ball and swimming suit technology can and do make the sport more boring.
Another problem with F1 is that it's not about pure skill and it is not a race about the drivers but rather it is a team sport. We have seen 1 mistake in the pitstop cost the driver his victory and vice-versa. Basically the team with the most money to spend on drivers, mechanics and research will always win and long gone are the days of outside companies making it because you just cannot beat Mercedes or Ferrari when they have so much more money to invest in the cars.
I still love watching F1 but there is no denying that the sport was at its very best in the 70s-late 90s where it was just far more dangerous and exiting, as well as being more about skill and innovation rather than whoever had the most expensive tyres, mechanics and sponsors. On the lower end of the grid, some of the drivers there have literally been bought by their billionare dads so that they could race in F1 *cough* Williams *cough*