Materialized views work pretty well in Postgres. But yes at some level of load it’s just helpful to have the traffic shared elsewhere.

But As soon as you go outside Postgres you cannot guarantee consistent reads within a transaction.

That’s usually ok, but it’s a good enough reason to keep it in until you absolutely need to.

Materialised views don't work well in postgres. They don't incrementally update and have to be manually triggered to rebuild from scratch