Spectre could too, but again, my point was that I didn't hear of actual attacks on people in the wild, at least not on any scale that seemed to make the news. Is there a reason to believe this will be different?
You never would. It's a passive attack. It's measuring response time to normal operations to discover secrets.
https://mlq.me/download/netspectre.pdf
"Software based side-channel attacks are particularly unsettling since they do not require physical access to the device."
It took 2 decades for everybody to forget about it before the vulnerability dismissed as "not exploitable in the practice" came back with a vengeance.