Referencing system tables to build a view

The main issue is that the Member table may be subject to change in a future release of OneStream, e.g. renamed columns, new columns, removal of columns, move of columns into other linked tables.
The documented methods to retrieve member information, by using a Method Query in a Data Adapter, or the BRAPI methods, are safer because they are documented and any changes to these in a future release should be properly notified in the updated documentation, as well as likely to be backward compatible.
The Data Adapter already has a Dynamic Member List as a built-in method, so you don't even have to write SQL.

There aren't many use-cases where I would recommend using an SQL to query the [Member] table directly, but one use-case could be if you are doing it from an external process (i.e. not a process that runs within the OneStream platform) which needs to pulls Member information from OS.