Likewise amrika never invested much in large sam systems but went for vast nos of attack aircraft and munitions.
That is a threat based difference. Simply put, there is no threat to the homeland that requires very long range SAM's. The threat that does exist is strategic and therefore the limited capability to fend off against NoKO missiles in the future.
The Medium/Long range Army system is the Patriot and with it they have emphasized magazine depth compared to long range. One example of this is the fact that the GEM-T, the 160km (TVM limited range) ranged weapon is really hitting the end of its development road while the much shorter ranged (though far more capable), PAC-3 was chosen for the path ahead given its H2K enabled high magazine depth (up to 16 missiles per launcher for the standard -3's). At best the new radar will give them the ability to lob a GEM-T at say 200km but there are really no plans to replace that weapon since 4 a launcher is really not optimal in a raid like scenario that they expect both in the Middle East and the Pacific.
This is largely driven by the needs arising form the system which are to protect forward deployed troops and infrastructure and not provide coverage to vast, fixed geographic areas such as cities, population centers, ports etc. The Army also deploys the THAAD which is a long-range BMD system (THAAD ER will extend the range by up to 3X and the defended area by 9-12X). Similarly the SM3 (not an army system, but used from land) enables very large coverage (AEGIS Ashore) - thousands of km can be protected form long range ballistic missiles using the newer block variants.
The Gulf War exposed a capability gap when fending off against saturation attacks from ballistic missiles that were expected to proliferate and get significantly more accurate (and this has occurred). This directly led to the ERINT and the PAC-3 (that was designed with highly capable short ranged ballistic missiles in mind) and now the MSE which while still in a small form factor (the standard launcher can pack something like a dozen of the larger ones) actually extends the range to the smaller MRBM's (around 1100 km ranged weapons) territory.
Unlike the US-Army, the Navy has required fleet protection from distance (the carrier's can't be everywhere) and therefore they have had a far greater need for long range sensors and shooters. The SPY-1 and SM2 and now the SPY-1/AMDR and SM6 combination provided/provides that. The SM3 family does the same when assigned to providing ABM coverage to vast swaths of the ocean or even land given its footprint
. Unless the US-Army thinks the USAF is not going to be able to provide air-superiority to it in the future, they are unlikely to invest in long range anti-air capability since given the current threats doing so would run counter to the the capability required to deal with the sort of threats they are likely to face. Cruise missiles are and are expected to proliferate in the next few decades much the same way ballistic missiles have in the past. This actually emphasizes sensors and shorter ranged/cheaper weapons to deal with these systems and their offshoots which blur the lines b/w a UAV and a missile. The cheaper the threat gets while still remaining credible the more and more investment into cheaper non-kinetic solutions come into play. You can't be shooting down sub $100,000 drones with half a million dollar missiles (this assumes a sidewinder)..
In case of India, both the major threats share a long border and both offensive and defensive scenarios involve direct anti-air, and anti-missile threats to the homeland.