No one "trusts the government enough" when it comes to his own taxpayer's money, so that is a moot point. I have always had a good laugh reading such things exactly from the people who chose to stay in their country, thus taking the brunt from whatever wrong policies, while being apologetic for someone who flew. The masochism is strong with these people. They do seem to loathe their choice a lot, which is amusing, as the opportunities to change their own situation are there, yet they approve of the choices of others, but not their own.It's his money, he earned it and you can envy him but he's still calling the shots on where he lives and pays taxes. Maybe he doesn't trust the government enough to pay taxes and doubts the money will be used for anything good other than pocket filling so he just gives it directly to the community through his foundation ? Just saying, most of us feel let down by our government on so many different levels here, who are you to blame him ( especially if you're not here ).
As for the 2nd part, when he's 38, Nadal will be 39 and Rog will be 44 so I expect him to be extremely happy with anything he wins or achieves as the before mentioned guys would be long since retired so virtually every achievement will be a record braking one. As would have been the Roger's 21st slam - that's the context.
Djokovic's financial contribution to the community is minuscule compared to the the money he would have paid in taxes, and that is clear to anyone not trying to twist himself in a pretzel to be apologetic about Djokovic's moves.
Your point about Djokovic being 38 is completely missing the context: the implication is, that there isn't/won't be parity in the circumstances between when Federer is 38 and when Djokovic will be 38, yet it is doubtful that he will achieve even what Federer has achieved. That is exactly the point: the competition. Djokovic is extremely happy with what he is achieving even at 32, I am sure. That won't make the competition better.