An interesting trend over the past few years has been how many of the popular static site generators and frameworks we rely on are tied to a company that aims to monetize usage of that tool (to be clear, I am not judging this – just noting its rise). In Jamstack, I feel this initially started with Gatsby but nowadays includes Next.js, Astro, Remix and Fresh. While the framework is open source, the monetization is often tied to services that deeply integrate with framework features on day one.
While they aren't owned by a company, tools like Eleventy and SvelteKit (part of Svelte) have development fully funded by Netlify and Vercel respectively. It's worth noting that this model differs significantly as, in practice, features of each are not tied to specific offerings from the service that funds them.