Actually, India has actually become fast in some areas (atleast by Indian standards). In missiles, Of the Astra series. Astra Mark 1 is in production, Astra Mark 2 will be in trials (currently Su-30s are getting modified to carry the missile), Astra MK3 SFDR has been tested few days back, rumours of Astra MK4 are floating (at least in idrw). Same with SAM. Development time of QRSAM has been pretty low say compared to previous versions. Nirbhay was also deployed last year. One test failed because they were trying to substitute the engine with an Indian one. Now Akash NG is there too. VL-SRSAM is also tested, ditto with the Rudram family.
I am seeing a pattern here. India struggles when it makes ambitious plans right in the first iteration. But once the first version is ready, the second version doesn't takes much time.
Tejas MK1 took a long time even to be ordered , compared that to MK1A at least by Indian standards has been ordered pretty fast. Not to mention, prototype of MK2 is already bring made.
All India needs to be is to remain humble and not bite off more then it can chew.
And Only internal changes no major aerodynamic changes expect few.MK1.A has been ordered but has it completed development? Is MK1 to MK1.A similar to something like block I to block II for JF-17? As if no significant changes but small upgrades here and there with subsystems.