In his recent video MKBHD said the same. He’s certainly a tech YouTuber (probably the biggest) but no where as techy as the average HN crowd. A lot of comments on fetter & reddit also speak about this.
That 50m+ figure is surely iPads in general, rather than iPads Pro? iPad Pro is specifically marketed to media production professionals as a viable replacement for a laptop, but media production professionals (like the aforementioned tech youtuber) again and again complain that it isn't good enough. It's certainly good for some professional tasks, like drawing, but it seems lacking for things like video editing.
I was really surprised by his review. His review made it seem like technical progress was not a worthy pursuit. We should be satisfied with the status quo and Apple should stop setting goals.
I think it was more of how the latest iPads are still just a spec bump. The hardware has been perfect for several generations, it’s the software that’s holding the hardware back.
Even if they made every single one of them buy a new ipad every single year that would still be single digit change of revenue for apple