The reason why Credit Heist are less frequent

"Shaeis;d-200397" wrote:
It's pretty simple they increase the number of Grand Arena per month up to 4 without changing the credits reward.

For every Grand Arena you can earn up to 1.8M credit if you take out every squad.
It's an income up to 7.2M credits per month.

So you get less credit due to the decrease of Credit Heist frequency but you can get more through Grand Arena.
I guess I prefer to earn more thanks to my skill than to RNG.

At the end they tune finely how much credit you get.