Dear i will give you a classic example of 2 businesses i am involved in Delhi and Gurgaon -

1) Real Estate
2) Custom house Agent

Many...
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private and large listed players of Indian real estate like Godrej, M3M, DLF, Eldeco etc. have been venturing in GT Road belt in last 6 months.
You would be surprised M3M and DLF sold out their products in same amount of time (less than 48 hours) in Panipat like they would do in Gurgaon and here we are talking about big ticket sizes like starting from 2.5 Cr onwards.

Godrej struggled to sold out in Sonipat and Kurukshetra despite aggressive marketing teams sent from Gurgaon. DLF and M3M who are much bigger and luxury segment players didn't even venture in Sonipat, Kurukshetra and Ambala.

Panipat and Karnal is a cluster where there is substantial demand of luxury services and amenities because of huge spending power and large economy. Divyanshu is right, due to proximity with Delhi and no availability of Premium trains people prefer own vehicles, you need to first give supply before gauging whether they can fill the trains. The other intercities you named also dont have much quota for GT road stations falling under Haryana because fact is they are serving Punjab.

Similarly, in Export and Import items which pass thru custom clearances, Panipat was 6th Sonipat 11th (excluding NCR cities)1.5 decades ago in this region, Ludhiana was on top but now fallen on 4th. 3 Haryana cities have overtaken it.
It is also a reference of rapidly expanding Economy in Haryana and stagnancy/ decline Punjab is seeing in terms of Economy. There is not enough supply of premium amenities on Haryana section of GT road, it will remain a stereotype till the time you don't provide enough supply. I am talking in terms of data now on the kind of business we get from Panipat mostly, followed by Karnal, Sonipat, Rohtak etc. This cluster close to Delhi is rapidly growing.