Ben Johnston tells us why we might not want to use row level security in SQL Server:
One of the primary reasons to implement RLS is to facilitate reporting and ease the administrative burden. This section covers some considerations for using RLS with the primary Microsoft reporting engines and gives you an idea of things to look for in your reporting engine. Some anti patterns and alternatives to RLS are also examined.
This article goes a long way toward explaining why I find row level security so rare in the wild and never implemented it myself: most databases I’ve worked with are either transactional or hybrid OLTP/OLAP, they’re mostly multi-tenant, and they’re accessed through service accounts. That’s just a no-go across the board.