If you have a redundant setup, you won't get paged as everything can just fail-over.
Yes, you could do this yourself but that would cost more and reduce the advantage. How many colo racks in how many data centres / countries do want to have to visit? Even with redundant hot spare fail-over you will need to fix the hardware at some point and will be running at risk until you do.
A hybrid approach can work, with colo for the base load and cloud for scaling spikes / redundancy.
I've heard this before, but it's basically not true. You still have hardware problems, you're just paying to pretend they aren't there anymore. If you want to do that, it's OK, but we need to stop pretending that throwing money at a problem makes it go away.
> Yes, you could do this yourself but that would cost more and reduce the advantage.
Compared to AWS pricing? No thanks. I've yet to personally see a company save money by using AWS (ymmv of course).
> Even with redundant hot spare fail-over you will need to fix the hardware at some point and will be running at risk until you do.
Sure, but that's generally where you save your money. And if you do it right, it doesn't have to be at 4 am
I know HN and StackOverflow do things this way but I don't even want to manage the OS these days. We used to host our servers on-site and it was a massive pain. At least with colo you don't need to personally worry about power or internet going down, but you still need to replace dead disks.