It says in 2018, mobile was 58% and desktop 42%. Optimizing for the 58% is fine, but when it comes at the expense of the 42% it is harder to justify just handwaving it away.
More interestingly, the above page indicates that while there are a greater number of mobile visits, they don't stay as long and are twice as likely to "bounce", which I infer means leave the page before spending any significant time.
So by those metrics, although desktop users are fewer, they spend more total time. Again, ignoring their scrolling preferences to optimize for mobile seems questionable.
I'm guessing the person who posted this works at a US-based publishing group, in which case mobile traffic is likely ~75%.
Scrollbar hijacking is a valid objection but I do wonder how many users in that 25% it affects. I'm on a Mac and the freaking scrollbar disappears after less than a second of non-use. I think I've pretty much ignored it since Mac started doing this...
