And also, some tools still break when using the non-default umask.

Yes, yes, we all run Postgres in containers, but if you don't, and you upgrade to a new Postgres major version, gladly using the Debian scripts that make it all more comfortable, while using umask 027, you will enjoy your day. Though I don't remember if those upgrade-scripts where from Debian proper or from Postgres.

Since that experience I always wondered what other tools may have such bugs lurking around.