I strongly believe that the BuSL [1] "Business Source License" is preferrably. It leaves the code as source-available for now, but eventually the code becomes open-source. It gives you a moat from which you can run a business. Or less of a moat, and more of a time-distorting slow motion field that your competitors are 4 years behind.

This is the license Hashicorp used. It means that abandoned projects never need to die. It means that the source code is publically available now.

[1] https://en.wikipedia.org/wiki/Business_Source_License