Typically, even as a pre-seed or seed company, you can rely on being able to raise your next round if you hit certain milestones in your key metrics.

For example, if you are a SaaS company, you have a good story and team, and your TAM makes sense, you could have previously hit $300k-$1M ARR and raised a Series A. Some startups were even raising A's pre-revenue. In the new environment, that ability will likely dry up.