Jans Aasman explains why semantic modeling is so important for a data lakehouse:
Data lakehouses would not exist — especially not at enterprise scale — without semantic consistency. The provisioning of a universal semantic layer is not only one of the key attributes of this emergent data architecture, but also one of its cardinal enablers.
In fact, the critical distinction between a data lake and a data lakehouse is that the latter supplies a vital semantic understanding of data so users can view and comprehend these enterprise assets. It paves the way for data governance, metadata management, role-based access, and data quality.
For a deeper dive into the topic, Kyle Hale has a post covering this with Databricks and Power BI as examples.