I just speced out a 6TB Dell server. Price? It is already at $600K, and I haven't fully speced it out yet (just processor, memory, drive). Maybe that memory requirement is high (though it is about what I would need); 1TB is somewhat over $200K.
For the right situation that sort of thing maybe makes sense, though I'm SOL if I need high availability (power out, internet flakey, RAM chip goes bad, etc leaves me dead in the water).
So I would need to stand up a million or more in equipment in several places, or just use AWS and suffer the scorn of someone saying 'you could have put that in RAM'. Yes. Yes I could have.
Well, I keep arguing against that, because you still get 90%+ of the maintenance work, plus some new maintenance work you didn't have before, to avoid some some relatively minor hardware maintenance. And you can get most of the benefits of non-cloud deployment with managed hosting where you never have to touch the hardware yourself.
I work both on "cloud only" setups and on physical hardware sitting in racks I manage, and you know what? The operational effort for the cloud setup is far higher even considering it costs me 1.5 hours in just travel time (combined both ways) every time I need to visit the data centre.
For starters, while servers fail and require manual maintenance, those failures are rare compared to the litany of issues I have to protect against in cloud setups because they happen often enough to be a problem. (The majority of the servers I deal with have uptimes in the multi-year range; average server failure rate is low enough that maintenance cost per server is in the single digit percentage of server and hosting costs). Secondly I have to fight against all kind of design issues with the specific cloud providers that are often sub-optimal and require extra effort (e.g. I lose flexibility to pick the best hardware configurations).
Cloud services have their place, but far too many people just assumes they're going to be cheaper, and proceed to spend three times as much what it'd cost them to just buy or lease some hardware, or rent managed hosting services.
Even if you don't want to maintain your own hardware, AWS is almost never cost effective if you keep instances alive more than 6-8 hours of the day in general. Your mileage may wary, of course.
I am reasonably happy configuring an old school Linux box. Heroku is much more of a pain in the arse to deploy to in my experience, despite much of the work being done for you already. Debugging deployment issues is particularly painful.