Hurr durr screwdrivergiri bad 30 years R&D + 10 years testing good, meanwhile, China doing photocopygiri, fucking carbon-copied F-22s, F-35s, MQ-9, S-300, S-400, Su-35 and literally anything they can get their hands on.
They will soon kick our soldiers down the Himalayas while we feel proud of our dephens PSUs ethical record of never copying anything and submitting patents of components outdated 50 years ago.
You are forgetting an important aspect of reversing engineering i.e. competency.
We never copying anything or infringe patents maybe because we are technically incapable to do so.
PSU are not a hot bed for cutting edge ideas or innovation on the other hand creating thinking is frowned upon. Their is also a lot of politics going around in these organization.
We just don't have the MIC/industrial ecosystem needed to do such works.
HAL even imports screws from Russia.
OFB developed the Dhanush gun only after it got hold of schematics, working and software for Haubits FH77.
We need another 25-30 years to have industrial infrastructure to copy stuff like PRC.
On a side note we take lot of inspiration (we copy) from Israeli technology
Our seeker on Astra and active seeker on Akash missile is heavily inspired from Seeker from Barak-8 (and possibly some aspect Derby RS-Seeker).
Our Uttam AESA also takes inspiration from EL/M-2052 radar. Even our EW suite took inspiration from EL/M-8222.