I'd say it's probably not the typical implementation. Mainly because it's a pain to implement and manage.

I guess that's why this was created though. It's definitely an intriguing tool.

I did shift in past from single database to sharded via citus. The actual migration was smooth, but 6+ months of work went into ensuring compatibility.

There's ways to nearly guarantee compatibility without actually using a sharded approach, like enforcing all tables have a uniform shard key.