Here is a purposefully pessimistic projection I made earlier this year.
2021: 25/102
2022: 19/121
2023: 12/133
2024: 5/138
2025+: 2/140
Even with this fairly quick decline assuming 2020 does end up being the peak year it still gets to 140 million so unless it declines even quicker than that for some reason 140m is likely the minimum it'll do at this point so while it's not one of the options 140-170m is the range I expect it to land in and whether it outsells the PS2 and DS or not I think it'll probably be close either way. Like I wouldn't be surprised if it ends up at the late 140's or early 150's or late 150's or early 160's.