I have been watching for Typst for more than a year but there are still things Typst can not do as easily as LaTeX, see https://qwinsi.github.io/tex2typst-webapp/impl-in-typst.html for examples. So, I do not agree with the statement that Typst can fully replace LaTeX, at least, for now.
Other than the product itself, there are ecosystem issues as well. LaTeX has mature support in editors such as Emacs. However, support for Typst in Emacs is still in development. Thus, for now, I will keep using LaTeX, but I would keep Typst as an option.
That page has a reasonable re-creation, with trivial usage at call-sites, of each missing feature though? The only one that looks a bit revolting is the large pipe example
I'll be interested to take a look once the site is back up!