That's the same mindset that messed up the LCA as a project so much, because we wanted everything to be indigenous and combined all developments at once, which increased the risks of delays and development failures multiple times and that although the one has nothing to do with the other!
You can develop Kaveri engine de-linked from LCA and could still integrate it later, if fully developed and mature.
You can develop a puls dopler or even an AESA MMR de-linked from LCA and could still integrate it later, if fully developed and mature.
You can develop indigenous weapons de-linked from LCA and could still integrate it later, if fully developed and mature...
So it's not about making us dependent on foreign techs, or not developing indigenous radars, but it's about to not make the LCA fighter dependent on the success of other developments!
LCA MK2 with GE 414 engine, RBE 2 AESA, FSO, Derby and current Paveway LGBs, would simply be available earlier, than if we wait for the indigenous AESA, for the development of indigenous IRST, for Astra and Sudarshan.