PG has had incremental view maintenance on the horizon for many years. I expect it to remain on the horizon for a long time.
What you're describing is amazing, and I wish I had it available to us. We've hand rolled far too many triggers to achieve the same thing, with all the expected problems you'd assume. I'm sure it could be abused/misused, but a batteries-included approach like that would be huge.
If you are hand-rolling them then I might suggest https://github.com/trickle-labs/pg-trickle#pg_trickle which at least reduces the labor involved in trying to get it up and running and appears to address a lot of the correctness concerns I've traditionally had (like a sync not firing correctly due to a mid-operation outage).