That's generally the economic case put out in cloud planning: a startup or expansion does great in the cloud with quick time to market, but once that business has matured and the risk is gone the assets move in-house because it's wildly cheaper.
And something that seemingly everyone forgets: it's not black and white... you can have some things in the cloud while you have some thing on-prem, leveraging scalable infrastructure and redundancy while also keeping your core assets fully under your control. It's pretty easy to make an internal S3 replacement, it's hard to make a better S3.
not necessarily. for each of these “we build our own cloud” stories there’s quite a few more stories of large enterprises saving tons switching away from their own cloud. BOA themselves know their savings won’t last and they’ll be switching back. They’re already in negotiations
But I would expect that a large established company would do better to create it's own reasonably priced reasonably managed infrastructure.
Sort of rent vs build/own.