Again looking at my own example here, I bought my PS4 Pro for Horizon Zero Dawn, that was early 2017. We’re now early 2023, that’s 6 years later. And last year (5 years after I bought my PS4 Pro) I did buy the cross gen version of GT7.You can look at it this way: On the last two years, Sony has sold a lot more PS5s than they have PS4s. People who bought a console recently are more likely to purchase and play games on it than people who had it for ages and already lost interest in the platform, or had their console break, or just stopped gaming altogether.
I think your assumption that people don’t buy new games for their console anymore if that console is not current gen anymore is very wrong. Especially now in the modern day that games are much more backwards compatible than in the past. One of the reasons I bought the PS4/PS5 Deluxe Exition of GT7 for my PS4 Pro was in fact because of this future proof PS5 compatibility.
However I do agree that the percentage of non-operational or neglected PS4 consoles is higher than that of the PS5 consoles. Note that in my previous post I already deducted a whopping 30 million units out of that 117 million PS4 numbers sold to take this into account. I’m sure the reality is different and many PS5 owners have sold their old PS4 on the second hand market, people who just bought these old used PS4 consoles will for sure be actively using them as well (why else buy them?)