If you want to set up an effective air defence ground environment,then you would need to deploy multiple levels of systems,both missiles and AAA in an overlapping pattern.That's why nations around the world deploys SAMs of different ranges.
For example,the Russians have long range SAMs like a plethora of S 300 variants and S 400 yet they have deployed multiple types of shorter ranged SAMs like Shtil,Tor,Tunguska,Pantsyr etc - why did they do it??You don't quite understand this logic either I suppose....do you??
If an LRSAM was answer to each and every possible threat then nations across the globe wouldn't have been deploying layered air defence networks.Shorter range SAMs and AAAs are needed to protect the heavier and longer range SAMs from enemy air or missile strikes.
Besides,LRSAMs like the upcoming 120 km range Barak 2ER,are much more expensive and hence can not be deployed in greater numbers,on the other hand,the Akash ESHORADS is far more cheaper and be deployed in far greater numbers to and thus can be used to cover larger parts of Indian territory.