Talking about 6 matches and taking definitive conclusion about "Fed 2017>Fed2005" is kinda strange no?
But we can also talk a bit about those matches.
First of all, Nadal himself was better in AO09 than AO17, i wonder if anyone would disagree with that. Most notably his movement on the FH side was way worse in 17. Also yes, Federer's BH was really good at this AO and he finally found a plan against Nadal which made a good difference. Yet, despite this completely out of the ordinary performance (see
Here ), it took him 5 sets to beat Nadal and the match was as close as their AO09 final. In 2009 Nadal was really, really better than in 2017 (absolute peak form of his career i'd say) and yet Federer won one more point overall.
So, Federer had to be better at AO09 overall than at AO17. Maybe his BH was better in 17 but it's debatable.
IW 12 vs IW17: once again, Nadal was much better in 12 than in 17. The 2012 match was played in a lot of wind, so it contained many UE. Number of winners are similar. No conclusion can be taken from this sample on how Federer could have been better in 17.
Miami 05 vs Miami 17: interesting comparison! Miami 05, Federer luckily escaped the Nadal by barely surviving in the 3rd and then rolled over a gassed opponent. In 17, it was a routine win in 2.
Certainly, Federer was certainly not prepared for the challenge Nadal represented for his BH side in 05 while their 3rd meeting of 17 was another opportunity to prove he had finally came up with a new approach (12 years later..). I think (i don't remember the 05 match well TBH) that Federer approach was a bit more conservative in 17 which explains the overall lower number of UE. Once again those numbers don't prove anything about how Federer would be better in 17 than in 05, except maybe on the BH side.
So overall, everyone knows well that Fed 05 >>> Fed 17. Fed 05 is one of the best season ever in the history of the game, while Fed 17 isn't. you proved nothing, but thanks for trying