My company has come to the same conclusion.
I work at a tech company that operates around 24,000 servers. We also believe we're saving a lot of money. But large scale infrastructure does take a fair bit of in-house expertise compared to using the cloud. Just for example, there isn't much in the way so usable bare metal fleet management software, from either commercial vendors or an open source project. But even with the incremental engineering costs needed to provide the software layer, we still think we're saving a lot of money. And those savings will grow as our business expands.