Yes, drives are going to fail. Yes, power supplies are going to burn out. Yes, god, you’re going to get new parts. Yes, you will have to actually talk to vendors.
Big. Deal. This shit is -not- hard.
For the amount of money you save by doing it like that, you should be clamoring to do it yourself. The concern trolling doesn’t make any sort of argument against it, it just makes you look lazy.
I point out to people that AWS is between ten to one hundred times more expensive than a normal server. The response is "but what if I only need it to handle peak load three hours a day?" Then you still come out ahead with your own server.
We have multiple colo cages. We handle enough traffic - terabytes per second - that we'll never move those to cloud. Yet management always wants more cloud. While simultaneously complaining about how we're not making enough money.
But for smaller groups that don't have large/sustained workloads, I think they can absolutely save money compared to colo/dedicated servers using one of multiple different kinds of AWS services.
I have several customers that coast along just fine with a $50/mo EC2 instance or less, compared to hundreds per month for a dedicated server... I wouldn't call that "ten times" by any stretch.
For the record, I have built (and currently maintain) a number of CoLo deployments. Our systems have been running for +10 years with very little failure of either drives or PSUs. In fact, our PSU failure rate is probably 1 every 3-4 years, and we probably loose a couple of drives per year. All in all, the systems are very reliable.
Ignoring failed hdds week likely mean very little maintenance.