Scalpers hurt consumers not the games companies or hardware resellers.
A scalper exists to make a profit on something. For them to make a profit they have to shift a product. So for every product that is snatched by bots/sneaky people there will be a product being sold. Yes some people will there fore have less to spend on consoles after buying a scalped product but the people that buy from scalpers want to buy it for a specific reason and would (in the case of consoles) have factored this into their purchases. So if they wanted it for cod, there limit would be cod + scalp price.
As for the article, it only references physical and this has been declining. Sony have also shifted to providing a digital only platform with the ps5. Factor in COVID with people not able to go and buy the physical games from game shops and you get the result of fewer physical shipments. Sony also chucked in 15 games to play through the ps+ bundle.
The only thing which can be taken from the article is - Physical sales are down.
My response to that is - yeah, its expected.