Trend: Leaving Firm within Two Years of Making Partner

I have noticed a trend among my friends and classmates, which is leaving a biglaw firm not long after making partner. What is driving this? Evidently making partner is not “making it.” For my group of friends, it’s more women than men doing this and they are departing for smaller firms or business roles at a company (i.e.: not OGC, but role that’s law related like compliance).