In finance, no one will trade on perm oracle/sybase installs for open source databases, even if they were free (which they are not - always have to pay for support). A couple of million $$ don't make the difference in comparison to a few hundred million $$ that have to go into replatforming, tools, skills.
In cloud/managed space, Postgres is also hit and miss - still no good cross-region option and frankly other than AWS RDS not many other managed Postgres services.
So, MySQL rules the cloud/managed databases, and oracle/sybase/mssql rule on prem.
In cloud/managed space, Postgres is also hit and miss - still no good cross-region option and frankly other than AWS RDS not many other managed Postgres services.
So, MySQL rules the cloud/managed databases, and oracle/sybase/mssql rule on prem.