The L0 public licenses come with grace periods, essentially free trials. Right now they're at 90 days, but will almost certainly shorten, perhaps to 30 days or less.
The utility of L0 is to make it possible to offer one set of public tools with, say, a noncommercial use limitation, but offer those who need to use commercially an easy way to buy the right to do that. "License Zero", as in near-zero friction.
Zero is impossible of course, because there will always be some friction in the additional step of getting a different license, versus not needing a separately license at all. But it's up to developers to decide what's best, in terms of optimizing leverage to command support, on the hand, and minimizing friction that puts a brake on adoption, on the other. Purely proprietary software with closed source is at one extreme. Hyper permissive licenses like 0BSD are on the other.