Why did Kareena lose the drive to succeed?

Kareena has been lazy and complacent for quite some time now and I wonder what made her this way. She is the same actress who excelled in Chameli, Dev and Omkara.

I don't buy the marriage/kid reason because other actresses like Kajol and Rani have done challenging roles after marriage. Rani in Hichki was brilliant, and she seems very much in form in Mardaani 2 as well.

But why is Kareena only comfortable in flowerpot roles or being part of multiple ensemble films? More than that, what makes her acting so lackluster in all her recent films?