I agree with lots of the points here. However one of the great strengths of the SQL family is the FOSS history. I doubt something proprietary is ever going win everyone over. At least I hope not.
I think any SaaS APIs that reach any degree of widespread adoption eventually get OSS implementations (eg S3's API is widely supported by FOSS and proprietary implementations). This evolutionary path is awfully similar to SQL's for better and/or worse.
Agree this is a necessary part of the change. Convex is working on our OSS strategy this year. Thanks for the feedback!