"NoSQL" encompases too wide a sphere to say something like the problem that NoSQL dbs are helping with is scaling.
Some NoSQL solutions are focused on extreme scale (Cassandara, HBase etc).
Some NoSQL solutions are focused on extreme performance (Redis).
Some NoSQL solutions are focused on developer ergonomics (MongoDB).
Postgres is an interesting option. It ticks the "good enough" box for just about everything, but doesn't ever seem to be leading the pack in any of the "NoSQL" categories. That's probably fine, since it does lead the "Open Source SQL Database" field, and that's a pretty important field to lead.
Some NoSQL solutions are focused on extreme scale (Cassandara, HBase etc).
Some NoSQL solutions are focused on extreme performance (Redis).
Some NoSQL solutions are focused on developer ergonomics (MongoDB).
Postgres is an interesting option. It ticks the "good enough" box for just about everything, but doesn't ever seem to be leading the pack in any of the "NoSQL" categories. That's probably fine, since it does lead the "Open Source SQL Database" field, and that's a pretty important field to lead.