AWS, Microsoft Azure, and CloudFlare – services run by gigantic corporations with endless supply of money and talent – all experience catastrophic, global failures that take innumerable other services down with them within 30 days. 
Meanwhile Wikipedia just keeps chugging along, globally stable and reliable as always. 
And yes, Wikimedia Foundation runs a pretty complex infrastructure:
https://wikitech.wikimedia.org/wiki/Wikimedia_infrastructure