I partially disagree with this argument. They sold some 10 million units in 2016 - it might be that because of the success and ubiquity of iPods and iPhones in the decade leading up to this, that people thought that the first Apple Watch was a great product (it wasn't, really IMO). Brand cache, or whatever, sure.
But you don't sell nearly 60 million units in 2021 off luck.
The number of Apple customers from iPod that transitioned to iPhone was x%,
The number of iPhone to AirPods was y%
The number of iPhone to Watch was z%
z < y
z < x
in a cumulative measure from a time frame of 3 years from launch. Defining the proportion of current customers to converted sales is where one can play words with defining luck vs. skill vs. rent-seeking. If you have billions units and only convert 20% vs. other products that convert 75%, then maybe one is considered inferior to the other - and to which I confer the title of luck.
Now the fun question would be if x < y or the other way around.