As the article says, with OpEx, your costs scale with your revenues. So when you have $0 revenues, you have $0 costs. You only pay for what you use. Instead, w

As the article says, with OpEx, your costs scale with your revenues. So when you have $0 revenues, you have $0 costs. You only pay for what you use. Instead, with CapEx, you go and spend $10 million on a data center buildout (raising a lot of money from investors which is work too) with $0 revenues coming in at the time, that's real money with no guarantee of any return.