There is axis freecharge plus cc which is very easily available which does the same. (Although it also has invite only gimmick, it's not that hard to get it)
It's also not capped. I personally feel its an underrated CC. Only difference is 2% return on all other spends. This one has 1% only.
I think problem is that they have created a CC which is beating everything else that they have and everyone wants to use it, even the premium card holders.
Also, there have been some technical difficulties with gpay recently, in last 5-6 months transaction success rate has been very bad.
So they are trying to control number of users to avoid market saturation and system issues due to overload.