The main problem with SIMD is it is a complex subject, even if not that good, autovectorization wins over what most common devs know about SIMD.

Well now you could in theory AI generate SIMD, which will be vibe coded, as those devs have no idea of its correctness.

I did see the article about that too. Don't know about "always" since there are applications like web backends where you're never going to add arrays of floats or something. Even if it's data science stuff, if that's in Python, Numpy is doing the SIMD for you.