While I agree with you that these are non-commercial, by now many of them have very big commercial backings. Many Postgres core contributors work at Microsoft,

While I agree with you that these are non-commercial, by now many of them have very big commercial backings. Many Postgres core contributors work at Microsoft, AWS, etc. who make billions of dollars selling Postgres-as-a-Service today. Those projects aren't inherently commercial, and great software can be built by passionate hobbyists, but often times the two go hand-in-hand