I think the tone here is getting a bit confrontational. Discussion is good as long as it's productive. I want to address a few issues/concerns.
GDPR is important, and regardless of anyone's personal opinions, it is the law, and must be followed. A GDPR extension would make this easier, especially on large forums that get frequent requests. That being said, the vast majority of forums can be GDPR compatible without a specialized extension. Both data erasure and providing a copy of data can be done manually per request. It can be slow and tedious, but if your forum never / rarely gets requests, it's not really an issue.
For large forums, a GDPR extension can be very useful, and at some scale, absolutely necessary. If requests are received on a regular basis, infrastructure and a standard process for dealing with them is a must. That's why I'm personally involved with the development of Blomstra's extension, even though I'm not affiliated with Blomstra. Development is
streaps central feature that should have been in v1.0
taking a lot longer than we were hoping for many reasons, but it will be done eventually.
Same could be said for a rich text editor, a tags system, a UI for installing extensions, and many other features. Including something into core isn't a business decision or a reflection of its importance. It's purely an engineering decision from the perspective of maintainability. Flarum extensions are first class citizens, and some feature being relegated to an extension doesn't mean that it's not seen as being important.