I'm not sure why you think zero revenue is the default state. That's generally only the default during the short period of time in between selling angel investors on an idea or proof of concept and getting a first round of VC funding. Somewhere in the middle of that is launching a viable product and demonstrating a potential revenue stream while convincing investors there is a sizable addressable market you can poach from competitors or convince buyers they need a service they've never had before. Zero revenue is otherwise a short sprint towards irrelevance and insolvency.
Startups with a little bit of runway have to cut costs now to extend it, i.e. staff cuts, or they're also on a short spring towards insolvency. All business negatively impacted right now are extremely adverse to new expenditures for the next few months, and might only be slightly less so for the next six months to a year after that. All spending not absolutely essential to keeping the lights on is getting cut.
My workplace had contracts with a number of startups (and some more established) that provide industry-specific services, and as a matter of course we insist on a "force majeure" clause in contracts. As a result we are strongly moving towards terminating those contracts. We are considering it even for one or two that are close to being mission critical, because revenue loss just through June is in the range of $30,000,000. That represents roughly a 40% drop over expected revenue for that time period. Projections for the next quarter are much, much worse, even in an optimistic "we might be slightly less restricted as a society in 2-3 months" scenario.
Given this environment, startups that do not supplant an existing service for a lower cost, have VC confidence and can "hibernate" for a time, or some other type of product that can help businesses stem losses rather than just make some activity slightly easier and more seamless... only those startups will weather this storm.