The reality is a lot of systems (especially simple ones) run perfectly fine on a single server with next to no downtime and all the additional redundancies we introduce also add additional points of failures and without the scale that makes these necessary you might actually end up reducing your availability.
How did you come up with that number? I looked at the link and just one of the outages listed on January 10 was 59 minutes. That alone makes the uptime worse than 99.99% for the entire year before it was halfway through January.
(99.995% means at most 26.3 minutes of downtime per year. See https://en.wikipedia.org/wiki/High_availability#Percentage_c...)
if you click the history it says 98.452% over 365 days.
Yes we do have a DR box in another data centre now, in case of meteorite or fire.
This used to be the norm. A single hardware / software box CAN be engineered for high uptime. It's perfectly fine when we choose to go the other way and distribute software over number of cheap boxes with meh software, but I get pet-peeved when people assume that's the ONLY way :).
Another thing is an exercise for system design where hyperscaling is not required and the thing is actually quite simple. Many who have specifically prepared by leetcoding and reading "cracking the coding interview" 10 times over will naturally overengineer everything trying to fit this exercise to those book patterns dropping all common sense, all the while not having actually built anything meaningful.
I think these people will mostly try to rest and vest anyway. Truly passionate people will pass since they have actually built something and will understand the exercise.