This article doesn't say that, what it actually says is "Over 70% of Steam users have a CPU with 4 or more cores."
Steam doesn't even measure publicize information about threads on the survey, which makes it near impossible to check because not that long ago Intel locked out hyperthreading/SMT on their low/mid-grade CPUs.
Additionally, and more importantly: the Steam hardware survey _obviously_ doesn't represent the average consumer PC.
The fact remains that virtually all systems except perhaps old low-end phones now have more than one thread. Not going multi-thread for anything that makes the user wait leaves significant performance on the table.
Low end systems (4 threads or less) have less potential, but they also have the most need for speed, making multi-threading quite important. And high-end systems have more threads, so going multi-thread makes a bigger difference.
Steam doesn't even measure publicize information about threads on the survey, which makes it near impossible to check because not that long ago Intel locked out hyperthreading/SMT on their low/mid-grade CPUs.
Additionally, and more importantly: the Steam hardware survey _obviously_ doesn't represent the average consumer PC.