I'll also note that I'm old hehe, and one of my first jobs we had a decent sized data center on site. Dealing with SANs, tape drives (auto tape rotators at the time were garbage), servers, etc... was a huge PITA. Packing up tapes and shipping them to another office for location redundancy was always fun.
The particular application I manage really suffers from low GHz and not having all data in memory. Ive run the benchmarks on EC2, certain reports that finish in ~5 seconds can take more than a minute on a comparable EC2 instance that costs about 10x as much. This application really needs the raw CPU. and yes we have a pretty large engineering team that has optimized all the queries, índices etc.
As far as replication, backups, etc. I set all that up, and honestly it wasn't a big deal. It's a couple short chapters in the Postgres book that explain it all very simply, how to configure, continuously (and automatically) test, etc.
I do agree that SANs are a nightmare. Thats why I ship all my WALs (PG backup files) to S3 (and eventually Glacier). That way I don't have to think about losing those files and it's dirt cheap.
I think there's a misconception that these kinds of configurations are too complicated for a single engineer to setup, with never ending maintenance required. In reality you can set it all up in less than a week and it only really needs maintenance when you want to upgrade Postgres (some settings may have changed). I'd estimate it takes about 5 hours per year of maintenance.
Self-serve infrastructure appears likely to become increasingly viable as we continue improving last mile delivery and expand fiber access. Will cloud become self-cannibalizing? Definitely maybe.
What cloud gets you is the ability to put your data/workload right at the core without having to make special deals with your local isp, and with a lot more resilience then you would likely afford unless your at least at the multiple 20 foot container full of servers scale of compute need.
https://www.cloudflare.com/products/tunnel/
https://github.com/cloudflare/cloudflared
https://developers.cloudflare.com/cloudflare-one/connections...
Edit: If anyone is interested in self-hosting, it's stupid simple with cloudflared. I have a 2017 Google Pixelbook running Ubuntu on custom firmware that's serving a Flask-based website. It sits on my desk charging while connected to a guest wifi network. It receives a 100/100 Mobile PageSpeed score and takes 0.8 seconds to fully load.
Hetzner cloud now has two US locations... Still no US dedicated servers though - those would kick real ass. Even if their current cloud offerings themselves are already ~30% of the price of the major cloud equivalents...
From DO I get all the benefits of a reliable company, scalability, automated backups etc etc. There's no way I'd change.
AWS is very cost efficient for other services (S3,SES,SQS, etc) but virtual machines are not a good deal. You get less RAM & CPU, with the virtualization overhead, and pay a lot more money.
Especially for Postgres if you run some tests with pgbench you can really see the penalty you pay for virtualization.
Maybe the sysadmin skill of being able to build your own infrastructure is becoming a lost art, otherwise I can't explain why people are so in love with paying 5x for less performance.
Hetzner is cheap and reliable in Europe, if you're in North America take a look at OVH. Especially their cost-saving alternative called SoYouStart. You can get 4/8 4.5ghz, 64 RAM and an NVME drive for $65.
(I have no affiliation with OVH, I'm just a customer with almost 100 servers, and it's worked out great for me)