Some slightly outdated information from PlanetScale [1] Especially now the have Postgres offering as well but most are still relevant. Most people would actually find cost reduction migrating. Similar story with Neon although I am more bias towards PS.

It is not that RDS dont work well. I think it is AWS being too greedy with their pricing and we have finally reached a point where it breaks our mental model on cost evaluation. And people are starting to look at alternatives.

[1] https://planetscale.com/blog/planetscale-vs-amazon-rds