100% uptime is unrealistic for big companies because at scale, it costs a lot. For example, replicating is expensive with transmission, storage and maintenance

100% uptime is unrealistic for big companies because at scale, it costs a lot. For example, replicating is expensive with transmission, storage and maintenance costs. When the Amazon incident happened, I did an analysis and found that the cost about triples if stored in an external data centre. Almost 6x cost if hosting overseas despite same company. I then understood why companies like Reddit do not aim for 100% uptime possible beyond the data centre. It depends on how much the customer (or client) is willing to pay that determines the uptime aim (I think Reddit's aim for example is 90% at least).