Thats because its design is old. We didn't have tech at the time. Everything had to be designed from scratch.
Almost all of the mission-critical techs (transmission, powerpack, thermal sight to name a few) that went into the Arjun are of imported origin!! And it's not entirely the DRDO's fault because who in their right minds would care to go through all the pains of developing those gizmos for such a paltry order??!!
And as for the gun, you do realize that a smoothbore gun, which is basically just a thick metal pipe is far easier and cheaper to produce than a rifled gun and in any case, OFB had been producing 2A46M 125mm smoothbores for a long period of time, so I don't agree with the statement that the DRDO/OFB lacked expertise in this regard at least.
Testing infra, lab infra, imports of crucial subsystems, certification, re testing, new GSQR, again re developing other systems. Not to mention talent for developing this. None of this existed.
All of that is true for the MkI and nobody is denying that but there is simply no excuse for the abomination that the MkIA is!!
Primary problem is poor design layout choices based on older knowledge.
Not just that, they couldn't even copy the layout of the Leopard2A4 properly.
Would be rectified and improved in Mark2
Sure hope so.
Regardless it was able to stomp T90S in most areas.
Yes, in terms of mobility (due to higher power to weight ratio and better suspension) and accuracy of the main gun against moving target (due to the use of a better FCS).
But that does not mean Arjun has got the T-90S (not the licensed version) beat when it comes to actual gun performance, since the latter has a significantly more powerful main gun in the form of the 2A46M-2 which can handle higher chamber pressure and has a greater EFC.
Nor can it beat the T-90S in terms of actual armor protection believe it or not.
Where the Arjun does excel at (and the T-90S sucks balls) is post-penetration crew survivability due to its isolated ammunition stowage and greater internal volume.
So there are pros and cons in both MBTs and the game is not as one-sided as that CAG report may make it appear to some people.
Cost is a factor of economies of scale. All that development and manufacturing infra cost a lot and it got distributed over too few numbers of orders.
Very true.
Besides what would happen when in a war Russkies charge 40 mil and say take it or leave it?
Again, this is really a valid concern.
Tanks wont survive loitering munitions either way no APS can protect against loitering munitions striking at near vertical angles.
Recent events in Armenia and Libya may portray such loitering munitions/kamikaze drones as this unstoppable wonder weaposns but that's because in both cases, the combatants in the receiving end were woefully underequipped and poorly trained as well in the case of Syria and Libya and they basically had no way to defend themselves.
But against a military, that is equipped with powerful all aspect jammer systems that cover the entire gamut of the EM spectrum, such as the likes of Samyukta and Himshakti and on top of that, passive detection systems, their effectiveness will be reduced by a significant margin since such loitering munitions necessitate a man-in-the-loop guidance method.