Given a non leaky abstraction, ignorance of whats under the hood is just fine.
It is unthinkable right now, but what will happen with Amazon/AWS goes bankrupt and no longer exists? All these AWS Certified Engineers who are not actually devops will suddenly be lost.
On the flipside, if you learn everything from the ground up and then jump on AWS or whatever service is available, you will be in a much better position when the day comes to move away and to something else.
Abstractions in something like programming languages is fine because the language won't simply disappear one day - you'll evolve as a programmer and will be stronger for it.
But I really believe someone will figure this problem out, and at that point Dev Ops will be done. There is just to much money to be made.
Or they could just read this document and move to GCP.
https://cloud.google.com/docs/google-cloud-platform-for-aws-...
Know the fundamentals, and you'll be fine. Everything else is rhinestone marketing.
Minus vendor lock-in. Once you have your infrastructure dependent on ELB, S3, Redshift and all the other AWS niceties, you are effectively locked into Amazon. Locked, in the sense that migrating out has a relevant knowledge cost (deprecation of knowledge of AWS, need for gain in alternative knowledge).
It's not a dumb choice, but it's also not clear for either side. Running your own iron is much much cheaper. For my case (email service provider), our bill estimate on AWS would be about 300k€/year, while running our own servers costs 84k€/year (split at 48k€ depreciation and 36k€ operational costs).
Something to note about US orgs: New depreciation rules allow you to depreciate $500K/year in hardware, in that year. That means that gear is yours, forever, whereas that $500K/year in opex to AWS is recurring forever.