When I started using git, it broke my brain. I wasn't really sure I understood it, but the idea of cheap local branches soon became the most important thing to me in a vcs, and everything became easier and so much faster. You could just work on code the way real life happens, not in some methodical pre-planned release schedule that always rubbed harshly against the reality of bug fixes and ever changing minds.
Planetscale is a lot like that transformation. We've been thinking of databases as this specialist thing, where the arcane knowledge required to make it perform well is a specialist role, and something completely untouchable by mortal engineers. While we've learned about the importance of good data modeling, we've dealt with a layer in our stack that is essentially static. Shipping features that require changes to a database schema sit and languish, because the pain and coordination required can often be too much for a team to want to deal with.
What PlanetScale has done is solve two massive problems in one platform. First, since it's built on Vitess, it Just Works At Scale. You don't need to fiddle with knobs to get it to perform well. You most definitely are not even in the top 10% of what is already running on Vitess, so you don't really need to worry about ever outgrowing PlanetScale. But the BIG innovation here is what is possible now that a database works the way the SDLC has evolved with git. Make a branch, change the schema, roll it out with your code. Just like anything else, really. Use the PlanetScale CLI to actually USE your database. Change the schema because it will make your code better, and don't worry that you're somehow going to do it wrong.
PlanetScale just made databases useful for developers beyond a nearly-static data store. It's a high-scale database that you can change like code. It will break your brain a little at first, just like git did. And then you'll wonder why the hell we waited so long to have a database this good.