It's true that the PS4Pro seems to have failed to generate much consumer enthusiasm, even though the only really hard data I'm aware of is from Japan. With backwards compatible consoles, what defines a new console generation is that new software doesn't have to be playable on the old hardware.PS5 will not compete with Pro ,because at current state Pro failed to bring enough ''satisfaction'' beyond only notable 4K resolution increase. IMO
However, if the consoles are compatible with the previous generation, and if the difference in capabilities isn't big enough fo a truly compelling shift in capabilities, it makes sense for publishers to target the previous generation and its large installed base, and let the owners of the new generation enjoy higher resolutions and such. Which means that new content is still bound by the capabilities of the old generation and the value proposition of the new gen is worsened.
There is a bit of a balance to be struck in order for the new generation to take off.