Ginger Grant talks about Personal and Enterprise Power BI Gateways:
The Personal Gateway takes the data and imports it into Power BI. If you want to extract data from a variety of different places such as an Oracle Database, and Excel Spreadsheets, the Personal Gateway will support this, and the Enterprise Gateway won’t. Remember the Enterprise Gateway only connects to three different data sources, and Excel and Oracle are not on that list. If you want to manage connection and refresh of the data as the administrator or provide access to the data to everyone who needs it, use the Personal Gateway.
It sounds like these are currently different enough that “both” might be the correct option within an organization, at least until Enterprise Gateway adds the missing features.