And were sued for doing so. Removing functionality from an existing product is not acceptable.
which is why they've announced this limitation before the 3060's release
To my knowledge they didn't shut it down, PS4 architecture moved to standard x86 PC so no longer advanced vector units available through PlayStation that you couldn't get separately in an easier to work with way. This led to the rise of the current Top 500 which are a mix of CPU and GPU.
No, they famously shut down the ability to use PS3s for this and got sued for it.[1]
Not ever having the functionality in the PS4 and later doesn't imply they didn't remove it in prior cases.