Probably a bunch of assertion types and general DX. Node:test is just a feature, Vitest is a whole product. The former might be enough for small packages but nowhere near useful for anything non-trivial.

for instance exiting the runner on the first error. and the diffs with node:assert are not as nice either compared to vitest.

i'm building a framework with minimal dependencies at https://www.plainweb.dev so i'm super excited about everything that node builds in (sqlite, typescript).

but there is a difference between supporting the bare minimum and actually making it nice to use day to day.