WordPress is very widely used, but it is not "60% of the internet" (or even 60% of the web) based on any statistics I see anywhere. Some sites say it's 60% of all CMS's; perhaps you may be transposing these stats?
Anyway, among WP usage, I would confidently wager that the percentage running in "cheap VPS" setups is declining fast each year. Many different reasons for this. The heyday of smalltime independent bloggers (on WP or otherwise) was a decade ago. Large SaaS hosts (including the official wordpress.com) make up a big chunk of WP hosting. Security is a huge issue with self-hosted WP. Companies using WP as a CMS aren't going to use a tiny VPS.
There are still a lot of WordPress instances on cheap VPS setups, don't get me wrong. I just don't believe it's still such a major force where it would make up a majority of new mysql/mariadb installations anymore.
No 90% of wordpress which is 60% of the internet use small local hosted mysql instances. No they don't setup a vm on aws.