Trump is the one who actually decided to go through with the creation of a distinct branch rather than having it as a command. I think it is fair to say he created it.

There are all sorts of politicians and military members who advocate for a distinct Cyber branch of the military instead of Cyber Command. If a politician ends up doing that, then he should get credit for creating it even though it has been a long time coming.

> distinct Cyber branch of the military instead of Cyber Command

It's not 'instead', it's adding a cyber branch to a different org chart. There are two major org charts in the US military:

The services, such as Army, Navy, Space Force, etc., which are generally defined by domain (land, sea, orbit) and whose role is to recruit, organize, train, and equip forces - to prepare them, but not to deploy or command them in operations.

The combatant commands, which are defined by geography - such as Africa Command, Indo-Pacific Command - and sometimes by geography-independent domains, such as as Space Command or Cyber Command. The combatant commands deploy the resources provided by the services in various combinations. Modern conflicts generally require resources from multiple services/domains working jointly.

It makes some sense - you want domain experts to train and equip them for their domain, then you must necessarily deploy them jointly. Who should organize, train, and equip sea-born forces? Probably you want the Navy to do that, not the Army. Who should organize, train, and equip electronic domain forces (I hate the term 'cyber')? Do you want your IT organization organized, trained, and equipped (think of the importance of each step) by the US Marine Corps, or maybe by some actual researchers, engineers, and experienced managers?