From what I understand, the problem is that Sony doesn't allow digital game publishers to put PS3, PSP, or PS Vita games on sale any longer, unless it happens to be a cross-buy game with PS4 or PS5. Apparently, it has been like this since late 2019. That's why some sites or forum posts that report on PS Store sales will highlight the cross-buy games, so that users of the older systems can see what's available to them.
Sony should lift this restriction, and allow publishers to start putting PS3/PSP/Vita games on sale if they want. Even if Sony doesn't want to give out any discounts themselves, at least allow third parties to do so.
Sony's possible logic against doing a blowout firesale (and I'm not saying I agree with this) would be assuming that anyone who's still really devoted to these aging systems will scramble at the bitter end to pay "whatever" price for games that will soon be permanently off the market. In their eyes, "whatever" price might as well be full price. Why take a $10 game and sell it for $2 or $4? If someone really wants that game badly enough, he'll pay the $10. Dropping it to $2 or $4 now would just be straight up losing money.
The alternative perspective (which is what I would align with) is this: If those games have been available for so many years and the consumer still didn't buy it by now, then you might as well give it a deep discount and see if he'll take the bait. Selling a $10 game for $2 is still getting you $2 that you wouldn't have gotten otherwise. Better to sell it cheap than to not sell it at all. This is why some publishers may be in favor of putting their games on sale--it's their last opportunity to do so, and would gain them a little extra income.
