More like having electricity in your main office. You don't necessarily need to own your own power source and battery bank if the reliability of the public grid is good enough for your business.
But if the public grid is only 98% reliable, and you need power 99.9% of the year, you do need a hot backup system.
Google isn't providing the service that is down for many customers x% of the time, but a service that can fail catastrophically and permanently for x% of customers.
As long as anyone can say that a Google robot permanently cut them off from a service that is important to them, without any meaningful recourse, you simply cannot trust Alphabet with critical pieces of your business, even to the extent that you can trust your local power utility to keep the lights on in your office. There are plenty of businesses that can operate without a backup generator. But nobody can trust Google, PayPal, Amazon, Stripe, L4, Square, et al to be their sole service provider for some function critical to the business.
Those businesses are trying to be Internet utilities, but are neither as trustworthy as nor as reliable as a regular utility. Would you be comfortable buying gas from the gas company if every so often they intentionally burn a customer's house down, then tell any aggrieved survivors to suck it up and get lost?