Just keep in mind that many packages don’t work with MathJax. If you use the Extended MathJax plugin, you’ll be able to include some packages and define macros, but that’s it. Many useful packages such as ‘tensors’, which I use heavily, aren’t there.
Note that no plugins work with obsidian publish, so if you go that route, you won’t be able to publish your notes for now (although the author of extended MathJax has a hacky workaround to get it working with publish that I’m not aware of).
What I’m trying to say is, if you’re an advanced LaTeX user, I probably wouldn’t port all your notes. I would only write some basic evergreen notes. It will be a nightmare otherwise.
Otherwise, you can just use regular expressions as @ryanjamurphy recommended and it won’t be too difficult, I’ve done that recently.
I use MathJax heavily in Obsidian and I honestly miss full on LaTeX, but the ability to link notes is worth the pain.