It has an extremely low ceiling. You literally cannot make consumer-targeted software if you want to survive while writing open-source code. Services and consulting is strictly B2B, and services and consulting for open-source software is capable of supporting a population of like 1% of existing software developers. Advocating for this dogmatic ideal that would cull the field by 99% is ridiculous.

I don't know how you came to OpenAI as an example given that they famously succeeded while going closed-source with the release of ChatGPT.