You can’t patttern match on an empty map - there’s some good information here that explains much better than I could as to why: Pattern Match On Empty Maps
Edit: Just for some clarity - Map — Elixir v1.12.3
Specifically:
Maps can be pattern matched on. When a map is on the left-hand side of a pattern match, it will match if the map on the right-hand side contains the keys on the left-hand side and their values match the ones on the left-hand side. This means that an empty map matches every map.
