That makes complete sense to me. OpenAI is selling shovels and putting $$$ into improving and selling those shovels.

Salesforce (and other app builders) are buying those shovels (AI) to lower costs to build applications

Keeping this analogy, I guess it would be like not using shovels to build a shovel factory. Obviously, OpenAI needs a group of very talented experts, which are not getting replaced by AI soon, but they hire for all kinds of positions, including regular software engineers.