I have a bit of experience with Neon when I used it for a hobby project but not PlantScale. I'm surprised anyone was using Neon if it lacked basic observability.

I'm skeptical of distributed SQL. Having spent my early career designing and being the sole contributor to a distributed DB, I'm always concerned about how these things perform when multiple shards are needed to resolve common queries. To the extent that these DBs are just abstractions over a single hot shard, I'm sure they do their job well ... but a multishard join has got to be slow.

I know lots of people have been working and researching them, one of my undergrad professors among them, so I'm looking forward to being impressed by them in the future.