Some aircraft are just perfect. The C-130, the C-47, Boeing 737, Bell Jet Ranger, Chinook, etc.
They came off the paper so well-designed that only minor changes keep them current.
You are correct. Some aircraft designs are as close to perfection as it gets, and you named the two best: C-47 (DC3) and C-130. I have flown on both, and, aside from the noise (especially on the C-130), the “honey buckets” on both, they are designed to fly, and fly, and keep on flying.