> "DB" already means 25 pins, so well, it's quite hard to both have 25 and 9 pins at the same time.

No, it doesn't. All of the D-Subs are readily available in high density versions:

  DA-15 | DA-26
  DB-25 | DB-44
  DC-37 | DC-62
  DD-50 | DD-78
  DE-9 | DE-15

There are also double density connectors putting 52 pins in a DB housing and whopping 100 connectors in the DD housing.

Also DE-15 is the standard connector used for VGA.

There’s also a now-quite-rare 23pin variant, which was used for the Amiga video port. Those connectors are getting harder to find these days, some people have resorted to modifying 25pin connectors when making Amiga video cables

DE-15 is none other than VGA.