So several points that are incorrect. The analogy doesn’t work because cake making is too close, it would be better to say they make cookies and are trying to make cake or something like that. The F-15 is most certainly not reverse engineered, and was instead over engineered because of the perceived superiority of Soviet airframes. Of course we later learned these claims were false, but it still got us to make a monster of a bird.

India is having difficulties with their jet engine, but that doesn’t mean they shouldn’t still be researching stealth technology. If they got their hands on the F-35 for even an hour they’d be able to learn more about the stealth, computer systems, and just general construction techniques. Every piece of that bird down to the screws is custom and made that way for a reason. Reverse engineering lets you take it apart and put it together different ways so you can say “Oh, that’s why they use screws that are flush with the plane, or why the engine is built this way.” That data allows you to build your own technology.

India lacks money, but also isn’t getting the full tech transfer for their planes. Why would they take apart a rafale when they only have but so many, and will still learn lots maintaining them. They need actual tech documents or multiple engines to tear down and test with to really get advancements.

It’s one of the ways their no real allies strategy is harming them. Sure your friends will give you second tier tech and help you maintain it, but only allies are gonna help you catch up.