Partially true. But license production of aircrafts did allow us to design and develop multiple subsystems and components of aircrafts. Su-30 MKI is made majority in India by value, including its engine from raw material stage. In fact it is more indigenous by value than LCA MK1A currently is. But the thing is, it allowed us to indigenise a lot of avionics, engine components and allowed private firms to gain experience in manufacturing fuselage components and other sub-assemblies.
Problem with firms like these screwdrivering foreign products is that they have no willingness to localise the way PSUs had as they could absorb operational losses or revenue loss. A private firm is profit first and is answerable to its shareholders. So they have no incentive to localise components to other Indian firms (unless an import ban or PLI-like scheme is introduced) which will increase the costs further in the short-medium run while also sending back royalties to OEM/Licensor who already have economies of scale of the components involved.
It is cheaper for me to buy components for a smartphone from china, assemble and sell than it is to localise the same components from Indian players that increases the costs multi-fold. More so, when we talk about defence equipment, not consumer goods like smartphones, that too of foreign IPR.
All of our supply chains have been developed thanks to PSUs whether license producing stuff or making IDDM products. So whatever little localisation these penny-pinching private firms are able to achieve, is because of decades of heavy lifting by PSUs. So I agree that when all advanced components are coming from abroad and IPR is not with you, such screwdrivering simply must not be entertained beyond a certain point.