I don‘t understand how India has an acanced space program but fail miserably at military aerospace.
Arguably, India's greatest achievement in space -- launching an orbiter around Mars -- was matched by the UAE.
That brings up the basical differences in an aerospace
industry vs a space
program.
India launches literally only a handful of rockets every year between 2 and 7 since 2020.
You cannot compare building 2, 5 or 7 rockets with the need to builds scores if not hundreds of aircraft when you put in an fighter order for your air force.
The rocket comparison is meaningless unless you are manufacturing spacecraft in volume.
Only the US (mainly SpaceX) and China are manufacturing like an industry for space. If India has a space industry that is launching in volume then maybe that would be an anomaly for the poor performance of their aircraft industry. But their space capability is pretty much on par with their aircraft industry. Neither is really good at scale that represent actual industrialization of the process.
If you look at the current launch numbers for 2025, China had 63 to just 3 for India. One is becoming an industry with an mass production eco-system nearing economy of scale while the other is literally less than a handful of projects.