Although stealth delays radar detection, its more important role is making stealth planes hard to target with weapons. The wide bands of radars that can detect the planes are not able to locate them accurately enough to target them with weapons. No stealth is invincible, so mission planning is also key.
The U.S. may not have enough pilots to win a long war against a peer competitor. It takes a long time to train pilots, and they don’t stick around because flying commercially pays more. The pilots we do have don’t get enough flying hours. The U.S. Air Force has similarities to Japan and Germany’s air forces at the beginning in WWII. Germany and Japan did not have enough pilots or a robust enough pilot pipeline to maintain skilled pilots throughout the war.
Advanced air forces are vulnerable to enemies destroying their planes on the ground. Having a cheap drone destroy your ridiculously expensive plane is a bad exchange. Air forces can build hardened shelters and decoys to limit the damage.