I found this interesting from a recent Gartner whitepaper written for CIOs and IT leaders investigating the strategic selection of composable SaaS+PaaS platforms:
"Beware of legacy vendors supporting a wide and disparate selection of underlying platforms and architectures underpinning their SaaS offerings. These are less likely to provide a unified API style or data schema that in turn will increase operational management costs and reduce interoperability and the ability to create new services, together with fragmented ecosystems."