They may be generally a better option, but they have their own disavantages. For example, JSONB fields in Postgres won't deduplicate keys, so if you have large keys, your table size will increase quite a bit (which also makes it harder to keep it memory).

Using an EVA, you can have a "keys (id, key_name)" table, and then only use the IDs in the values table, reducing that waste.

By the way, you don't need views for indexing on JSONB fields, it's supported out of the box in PG.