You are right about the Pure Aero (Aero Pro Drive at the time) being originally made for Nadal due to his forehand style.
However, you are wrong on both other accounts. Pure Aero VS and Pure Drive VS were just made because there was some vocal demand for the two most popular 100 sq. in. Babolat racquets to be offered in the 98 sq. in. package.
Felix originally used the Pure Strike racquet and later switched to the Pure Aero VS Tour, which was basically a re-brand of the Pure Storm racquet when it released in 2016.
Our player profile for Canadian tennis star Felix Auger-Aliassime, find out: what is Felix Auger-Aliassime's racquet?
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Additionally, there's nothing to suggest that the Pure Aero VS 2020 was designed for Alcaraz. He grew up using the Pure Aero and simply switched to the Pure Aero VS after release. Furthermore, it has all but been confirmed that both Alcaraz and Rune have switched to the new Pure Aero 98, as evidenced by close-up pictures showing a lack of the oval grommets that are found on the Pure Aero VS 2020.
Is Alcaraz playing with the Babolat Pure Aero 98 or the Pure Aero VS? Let's look at the details of the racquet specs.
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As for your last point of these racquets being "very stuff and direct feeling, made for competition and hardest possible hitting. Not comfy at all, and not well adapted to the average buyer." everyone is different and has varying tastes and likes. There's plenty of players out there who like these frames as well.
Hope this was helpful. Cheers.