I gave you the full picture, but like many others here, you're completely locked in your view and there are no facts or arguments that can turn you away from what you - for reasons unknown - think is true.
Your 2 examples are matches, he could have won. Not should have won. If anything, Djoko should have won that obe sooner rather than going to the fifth.
Djoko won 12 more points, won 35 % of his return points vs. 31 % for Delpo and converted a mere 3 out of 15 BPs, cause Delpo was clutch down BP - even without having a great serving day (4 aces to Djoko's 22!). Delpo went 2/7, i.e. less than half the chances to break.
http://www.atpworldtour.com/en/play...verview/match-stats/540/2013/D683/match-stats
https://www.theguardian.com/sport/2013/jul/05/novak-djokovic-del-potro-wimbledon-semi
Fed-Delpo Olympics, a better case, sure, but again - he won fewer points (6 fewer) and had half the chances to break (2/7 for Delpo, 2/13 for Fed). I.e. Delpo more clutch at saving BPs. Despite being the worse server on the day (11/5 aces and DF's vs. 22/2 for Fed).
http://www.atpworldtour.com/en/play...overview/match-stats/96/2012/D683/match-stats
https://www.theguardian.com/sport/2012/aug/03/roger-federer-del-potro-olympics
As for Djokovic, taking a set of him in the years he did, was a feat in and of itself. Djoko ain't a good match up for him, yet he still made a fair number of them somewhat close. The few he's one, have also been close.
Again, you have no case.