Hahaha dude, stop posting stuff that are so easy to disprove. Go to any PoE streamer/youtuber posted here and check their analytics, D4 is not even close to been their most watched game. It's stupid point to make anyway.
Please link those analytics. All these guys made tons of money on D4, that's why you don't get clear cut answers.
There is no angle here where you can possibly defend level scaling.
There's a very simple angle. Play the game, compare with other experiences.
For example poe: if you level fast you're always underleveled or medium/slow and always overleveled. But outside of act 2, there's always same level scaling effect. People usually keep progressing and games are tuned easy enough there's no need to stop at some point. On top of it there's usually xp penalties/gains that help you along the intended curve.
If you want to have a linear path through the game you can adjust monster levels manually to that curve. If you decide to offer a larger amount of freedom you can't do that and level scaling is a good solution. It also fixes group play, provides more content for later etc. Overall the feeling while leveling is pretty similar.
Even the lucky drops spike and taper off in a similar way. But guess what, in D4 now you have the boogieman level scaling to blame it on.
Take your own hint, stop parroting easy takes from streamers with monetary interests.