Redshift -> Power BI OR Redshift -> SSAS Tabular -> Power BI?

We want to host Power BI on premise inside AWS.

Our unique datasource will be one flattened table in Reshift

Some of us want to load the Redshift data into an SSAS Tabular model and report through Power BI using the SSAS model as a datasource.

It seems to me that it would be simpler to load the data directly into Power BI rather than through SSAS since both are Vertipaq engines.

I suppose an entreprise license would cover both Power BI Report Server and SSAS...

Are there any advantages/disadvantages in either approach?

Thanks

Eric