In the article they write about the early days
We raised a $7 million seed round
Why do investors invest into people who build something that they give away for free?If your userbase or the current CEO likes it or not.
Why invest into a company that has the additional burden of developing bun, why not in a company that does only the hosting?
There's also the trick Deno has been trying, where they can use their control of the core open source project to build features that uniquely benefit their cloud hosting: https://til.simonwillison.net/deno/deno-kv#user-content-the-...
(It was reverted after the situation gained visibility, as is tradition.)