Many of the functionality people associate with source control programs live inside the group one drive which is created for Power BI. Looking at the picture of the group screen, which was created when a Power BI Workspace was created, you will see that this group contains 7 members and four files. The members of this groups are the only ones who have access to the files. The file AcmeThree.pbix is selected, and cClicking on the elipise (…) brings up a menu for the file. Notice one of them is Check Out. If I check out a file, the icon next to the name changes, providing a visual queue to all who wish to edit the file that it is being working on. The menu option for me would change to Check In, providing the ability to check the file in to the directory, allowing others to check out the file and work on it. Notice Version History also exists. This feature allows previous versions of the file to be loaded, which means that changes made to a file can be rolled back.
It’s good that this is available, and I’d make use of it. For Power BI Desktop, it seems prudent to continue using source control.