There are no miricles
Being responsible for many DCs and a large enough infrastructure, I can tell you no matter how much you invest, things happen.
The larger you get the more variables there is in the equation, look into the simpliest of things for us this days, Internet connectivity. Any ISP, despite whatever people stated here, I've worked in several big enough, daily their NOCs are flooded with failures, 99.9% they aren't service affecting, or cause minor flaps, barely noticible by the end user. and then there is 0.1% of causes that causes a big mess for a while, but almost always things are recovered in a very short time if you think about it.
Some people prefer to have email servers at home, can you share your home electrical bill with us please? or have you ever though that your house could have caught fire and you would be crying at this point because your house was on fire?
And how much it costs your contingency server in some ISP as you claim? does it really worth? I don't believe your eail is that important :).
If you want to manage because you are an entosiast is fine, you can always get 2 or 3 virtual servers in different low cost providers, for the specs you present, theses days for a couple of euros the trick is done.
Availability isn't the reason Cloud is better or worth than anything, tell me 1 company that never ever had IT problems, that is operating for more than 2 years... Google, Azure AWS, Digital ocean, Banks with internal team, or even NSA that was hacked not that long ago.
Besides I think we all prefer to be screaming at someone to fix the problem, than to be screamed at us to fix a problem... and this is the real reason Cloud is so successful, as well outsourcing before of that (like millionaire IBM contracts in early 2000s). You can always blame someone else instead of yourself for your choices.
There isn't a perfect solution for everyone, so chose what makes sense for you economically, in terms of privacy and risk that suits your needs and make you happy 90% of the time and lets you sleep. All of the solutions have their risks, I wouldn't be comfortable to have a DC at home without minimum security conditions.
So stop the type of conversation, mine is bigger than yours... not all the ladies like them big!