Those trades are good by accident - the Flyers dismantled a team that went to the Stanley Cup Finals the year before, one with an elite defenseman who was getting old and only had a short window to be great. You also have to factor in the giant goalie signing which was a calamity, the 35+ contract given to Pronger that Holmgren did not think was 35+ (even though the CBA is incredibly clear on this point). So yeah, Mike Richards is aging faster than you might expect and that contract isn't looking too hot these days.
Both the Carter and Richards trades are wins from an asset perspective and have kept the Flyers an okay team despite getting poor to mediocre goaltending. And yes, the Flyers draft very well too, although it's strange how they draft excellent forwards and cannot draft D at all, but the team is a mess of bad contracts and overall average talent, and there isn't a ton in the pipeline to help out. Gostisbehere might be something, Laughton looks to be another solid player, but they don't have much else there. I also tend not to credit general managers with draft pick successes - they have too much on their plates to be scouting.
And let's not forget James Van Riemsdyk for Luke Schenn, probably the worst major trade of the last 3 years. And giving away Bobrovsky for picks.