They are, but there are still some startups that use options. At least the liquidation is easier with the RSUs, but it doesn't prevent the fall off post IPO as

They are, but there are still some startups that use options. At least the liquidation is easier with the RSUs, but it doesn't prevent the fall off post IPO as people wait (rightfully so) to see quarterly results employee cashouts before taking a stake in whatever the narrative is. Switching to RSUs was a good decision, particularly after so many Google employees were borked with underwater options around 2008 that took until about 2009 to correct.