Semedo is not a flop because he is not as good as Dani Alves.
As I explained in another thread, there are only 3-4 RBs at the moment in the world that are rightfully considered better than Semedo. Then it's the old guard that is retiring,
And then it's Semedo.
Market and interest from other clubs says so, irrespective of what you think about his attacking output.
Fati was the fastest this season alongside Semedo, alba, and braithwate. Just look at his highest recorded speed.
Fati has a 33.8 km/h, which would be in the top10 LaLiga players or somewthere there. He is right below Mendy in
this list. But given his agility and ability to turn while running that other players don't have, makes this speed even more valuable (for example Nacho recorded a 34.6 a couple of years back, but Nacho cannot turn or dribble. So his speed is only useful when making a sprint to return to defense. Fati's or Dembele's speed, on the contrary, because they are agile and can dribble, so they cannot only catch a long ball but can also run with the ball and go past opponents at some percentage of that speed, has higher proportional value)
Now, @khaled I cannot browse all the pages of Fati's thread to find the argument why he is not fast. Maybe you can repeat it if you remember it.
As for his aerial abilities, when he can jump so high to score a header that current day Suarez could not have scored, then it shows something. He is not used as an aerial threat in the box, because his other skills are more wanted, and rightfully so.
But he can be an aerial threat, especially when coming from the one wing to meet cross coming from the other wing.
As for his shooting, look at the goals against Inter Milan and Leganes recently. Perfect accuracy, spotting the opening even between defenders' legs, enough speed to beat the goalkeeper. No ricochet or anything like what you say. Maybe study him again. Shot power, like I said above, usually develops later in the age of a footballer, so I don't even consider it as a problem.
As for the rest (@BBZ8800) I will reply later. Your arguments suffer from logical gaps and inconsistencies.
By the way the Ronaldo video you posted is from Ronaldo aged 20, not 17. Big difference.