Phasing out couchapps was a bummer indeed, it was what originally got me excited about CouchDB. But regarding querying and performance, they have come a long way, the MongoDB-like queries are as fast as the views and allow you to do things that are indeed cumbersome with views. In my attempt at a NOSTR relay storage, I'm not touching views at all at the moment, it's only these Mango queries. I find the views API helpful when you want to use the reducer functionality to easily sum/average millions of records. Recently they added a built-in full-text search engine which is really nice to have to avoid external dependencies.