Jsdelivr provide marginal benefit at some cost, which aren’t worth it in my opinion.
The only place where we use jsdelivr is for serving MathJax, for which it is the canonical source that Mathjax links to in the documentation, which seems good because it allows people to cache Mathjax for multiple sites, so I think this is the best solution here. Seems worse for us to set up our own CDN, and worse for it to be served from the LessWrong server, since that makes our job harder.
The only place where we use jsdelivr is for serving MathJax, for which it is the canonical source that Mathjax links to in the documentation, which seems good because it allows people to cache Mathjax for multiple sites, so I think this is the best solution here. Seems worse for us to set up our own CDN, and worse for it to be served from the LessWrong server, since that makes our job harder.