In my experience, a non-finetunable closed source API is a complete nonstarter for a large fraction of possible use cases, especially the higher value ones like law and engineering. Most of these embedding models are trained too much on colloquial use of language on the internet that has little overlap with how terms of art are used, and without the ability to fine tune it to a specific use case, they're only really useful for generic use cases and even then they can be limited.