Good opportunities arise for those who stick their neck out. Here's some inspiration for what to blog about: https://simonwillison.net/2022/Nov/6/what-to-blog-about/
It seems he started his blog in 2003: https://simonwillison.net/2003/Jun/12/oneYearOfBlogging/
And ever since Nov 2022 and beyond, his blog is now majority riddled with non-stop AI, LLMs, Chatbots and Agents slop which is what the parent comment is talking about.
As for the "browser is the sandbox" running untrusted code in the user's browser increases the risk of an unintended RCE via a sandbox escape which can be done in Chrome [0]. WASM is not going to save you either [1].
[0] https://www.ox.security/blog/the-aftermath-of-cve-2025-4609-...
[1] https://issues.chromium.org/issues/334120897