I think as headline "one million queries per second" is not particularly exciting these days. MySQL 8 had shown more than 2mil simple queries/sec few years ago and more than 1 million just IO bound queries
The great thing with PlannetScale and Vitess is what it is horizontally scalable while MySQL itself is not, though you need higher headline number for things to get exciting.
https://www.mysql.com/why-mysql/benchmarks/mysql/
The great thing with PlannetScale and Vitess is what it is horizontally scalable while MySQL itself is not, though you need higher headline number for things to get exciting.