Teo Lachev builds a pair of tables:
Here is table that is getting more and more difficult to find as searching for Fabric capacity limits returns results about CU compute units (for the most part meaningless in my opinion). I embed in a searchable format below before it vanishes on Internet. The most important column for semantic modeling is the max memory which denotes the upper limit of memory Fabric will grant a semantic model.
Click through for that table, followed by a table comparing Fabric SKUs to Power BI SKUs.