Yes, there is not much at release which really screams "damn, I need a new console for this" but delaying the consoles doesn't change anything. Just release them this year and those who think the consoles are only worth to buy end of 2021 can buy it 2021. What does it matter? Even with not many unique experiences they will sell good the first half year.
There are also many who still own as example the standard XBO and those will experience a huge jump even for cross gen titles. I mean, these people often play with below 30fps and 900p (or even lower). I'm sure there are some of them who will buy a new XSX or PS5 at release. That argument that he doesn't even have a 4k TV now is just useless.