If I were to bet on my hunches: At least half, leaning more, of that 20% buying SATA SSDs is probably momentum of people who didn't know they could get a better performing m.2 NVMe drive for the same price. Few people are upgrading PCs with SSDs for the first time in 2025 and those that are probably didn't really need SATA, they just searched for SATA/saw SATA.
I don't really know how one would get numbers for any of the above one way or the other though.
I remember running my first NVME drive via a PCIe adapter on my i7 4790K about a decade ago... man, that was a game changer for sure, almost as much as going from HDD to SSD on SATA around 2009.
I prefer SSDs because the connector is so much more accessible. Ripping out the video card and futzing with the pain of that tiny NVME screw is no fun.
I am almost never IO blocked where the performance difference between the two matters. I guess when I do the initial full backup image of my drive, but after that, everything is incremental.