Surprised not to see this mentioned in the article.

Lots of places (including a former employer) have done tons of work to upgrade internal infrastructure to support HTTP/2 just so they could use gRPC. The performance difference from JSON-over-HTTP APIs was meaningful for us.

I realize there are other solutions but this is a common one.

Probably because it only works correctly outside of browser. Browsers don't support "native" grpc. You normally use something with specifically gRPC support rather than just h2 in a spherical vacuum.

This entirely. When I first read the title, I thought, lets see what they say about gRPC. gRPC is so much nicer working across applications compared to simple REST servers/clients.