Agreed. 10M should be 100% doable this year. 11M-12M if there's a deep price cut. That would put it at ~119M-121M. Hard not to see it shipping another 10M in the 3 years after that.
Problem is that not only those sold through predictions are unrealistically optimistic, it also ignores actual sold through vs shipped logic. Ps4 sold around 106m by the end of 2019 and an old console will have less and less difference between shipped and sold through until discontinuation. Should expect something like 8-8.5m this year and exponential drops every year after that.