Eagles roster is superior, to even the Chiefs roster...let alone the Cowboys. Hec, the Eagles roster is probably a bit better than the best of the Cowboys, Commanders and Giants collectively.
And it all starts with the trenches. Their front 4 controls the game, so then calling defensive plays is rather easy (just stop the run, and then sit back with 7 defenders on pass plays, rushing only 4). And with Saquon, calling offensive plays is rather easy, because for most passing plays, the Dee is locked up in 1-on-1 man coverage because there are 8 and 9 men in the box to stop Saquon. So the passing game can be basic.
It's easy football, when a team is built right. The Cowboys of the 90s were this way too...it was basic football. A lot of Emmit Smith because the o-line was so dominant, and a lot of coverage defenses because the Dee line was super strong.
Football ain't rocket science. You don't HAVE to have a Mahomes to win a Superbowl, you need a team built from the inside out.