I'm so surprised there is so much pushback against this.. AWS is extremely expensive. The use cases for setting up your system or service entirely in AWS are more rare than people seem to realise. Maybe I'm just the old man screaming at cloud (no pun intended) but when did people forget how to run a baremetal server ? > We have 730+ days with 99.993% measured availability and we also escaped AWS region wide downtime…
That said, I've seen real world scenarios where complexity is up the wazoo and an opex cost focus means you're hiring under skilled staff to manage offerings built on components with low sticker prices. Throw in a bit of the old NIH mindset (DIY all the things!) and it's large blast radii with expensive service credits being dished out to customers regularly. On a human factors front your team will be seeing countless middle of the night conference calls.
While I'm not 100% happy with the AWS/Azure/GCP world, the reality is that on-prem skillsets are becoming rarer and more specialist. Hiring good people can be either really expensive or a bit of a unicorn hunt.