Owned it. It was campy fun even then but WCII and WC:Privateer were far and away the better games. III was one of many attempts at a game-movie crossover that never really worked imho. Privateer is the basis of EVE online, Star Citizen and countless other modern titles. In terms of influence it is up there with SimCity and Civilization. https://en.wikipedia.org/wiki/Wing_Commander:_Privateer
The ending was certainly cathartic after everything that had happened from the beginning until that point.
Oddly, I feel like Prophecy may have had the best fleshed-out flight system, but I wasn't a huge fan of the story. WC4 had the second best ending, though! Only behind SO2 in terms of relieving you of the frustration.
Privateer is definitely an interesting game, and it's really weird that they never really tried to follow that model again. Privateer 2 is best not brought up, and by the time any theoretical P3 could have been in development Origin was already dead.