Is there a way to embed existing Power BI reports in this type of site? Obviously we do not want to redesign our existing Power BI reports using one of the listed tools. I would like to know if there is any kind of integration between Power BI and a Sharepoint Business Intelligence (BI) Center site.
@LindaH665 That BI Site template has been around for many years, it was a good option before Power BI existed and was primarily used on-premises. Most of its functionality has been superseded with new techniques.
Since you are already using PowerBI, I would recommend focusing your design efforts on using the Workspaces in conjunction with SPO pages/PowerBI web parts, and Teams w/PowerBI tabs.