Ask HN: Why are there no open-source Remote Browser Isolation solutions?

So Remote Browser Isolation is basically remote desktop for the browser: There is a browser running on a server, with the image streamed to the client on a canvas. There are a lot of commercial offerings (Cloudflare, Proofpoint, Zscaler, BrowserBox), but strangely nothing open-source.

~2 years ago, BrowserBox was trending on HN [0] and went open-source shortly after [1]. However, they have since walked back on this and made it fully commercial again. Today, they replaced the README with something which is, dare I say, deranged: <https://github.com/BrowserBox/BrowserBox>. I assume their commercialization efforts have not gone as planned, hence the desperation.

Back to my question: Why are there no open-source Remote Browser Isolation solutions? Is this simply a space that's uniquely "enterprise" with entrenched players, with no room for smaller projects to strive?

[0]: https://news.ycombinator.com/item?id=35490289 [1]: https://news.ycombinator.com/item?id=36464653