I think it is clear that Ferrari has the biggest potential to comeback better. Because, they do not even need a car improvement to be better. They just need to go back and watch all the mistakes they did about pits and their timing, and they could end up with a much better second half of the season.
Don't get me wrong, I am not saying that other teams suck or anything, sure Mercedes could get better, but if Ferrari has a great strategy improvement and pit amazingly and correctly each time on perfect laps and right tires etc etc all great, then we are going to see them get a ton more points instead of losing points out of nowhere without a reason.
If they could have done it, they would have done it already. It's clear that there is a talent to be a strategist, a race engineer, and team boss none of which Ferrari has, even if they want to, they will always fail because they are not good at it. Give the whole team outside of car and driver to Red Bull and red bull would have been bad this year, same car, same drivers, too would have taken them to top.
So, it's all about the staff part and they can't get better, only if they somehow hire new people all around. Red Bull will be good enough, Mercedes will become second team and Ferrari will drop to third, and that's how we are going to finish off the season.