Eventually, the cost structure means your team has to reach for infrastructure-as-a-service providers such as AWS, Azure, and GCP.
I'm presuming most teams move from PaaS -> IaaS more frequently than the other way around. Did you do a direct migration or is there some middleground cloud provider such as DigitalOcean?
Is this an interim buffer area where you quickly try to move to IaaS, or has your team lingered halfway between IaaS and PaaS?