This was probably the gen to do it. Last gen PS4 started with a bang with being $100 less than the X1 at launch and being more powerful. PS3/360 gen numbers are pretty much equal with PS3 catching up and being very slightly ahead overall in the end. I believe PS3 sold 86-87 million and 360 84-85 million or something like that globally.
If MS did it this gen and went with $399 with the XSX and stating themselves that it is more powerful on paper, they would've gained huge momentum.
Now that they are the same price and multiplatform differences are out and showing the 2 consoles pretty much on par with each other and exchanging virtually equal blows, people will go with the PS5 because they know PS4's track record with exclusives and will just go with familiarity and where the big hits are. Also PC gamers may tend to go for PS5 more because they can play all the MS exclusives on their PC's. There are more than double the amount of PS4's globally compared to the X1 so naturally, friends will go with the console their other friends are on.
Having said this, both are selling out pretty much what they can produce at this moment so will have to wait for when stock is more abundant to make a better gauge.