And then all of a sudden you run into more engineering costs. Companies use platform services because one dev/engineer can do a lot more on their own and focus

And then all of a sudden you run into more engineering costs. Companies use platform services because one dev/engineer can do a lot more on their own and focus on delivering business value rather than twiddle knobs. And adding one dev/engineer is _massively_ more expensive, so you seldom want to scale in that axis when the option is to, say, use a managed database or even a complete data pipeline.