Up until 2016-2017 most enterprises where using mainly basic infrastructure-as-a-service for their cloud platform, leveraging the operational benefits as well as some coveted optimization. On the other hand, they were consuming a lot of great SaaS components but these were normally satellite to the major cloud vendors. In 2017 and more towards 2018 the cloud vendors had matured their compute platform, they created services that do not exist and most probably will never exist in private clouds or self-hosted data centers.
The existence of those advanced services which are much beyond IaaS, like managed containers, function-as- a-service, data lakes, IoT platforms, edge computing, Mobile components, and artificial intelligence is the tipping point and knockout to the self-hosted data centers and private clouds.
Enterprises are in a competition with themselves, fighting the time to avoid getting hit by a disruption that leverages those available, super advanced technologies-as-a-service. The cloud market has created an equality, anyone can get the same technology at the same click of a button for the same low cost, pay-per-use model, this means there is no longer more advantage to corporate giants.