They just need to make a proper GT7.
No one's saying they should now make a GT6 Remaster. It's too late for that but if PD is developing GT7, PS5 should also be on their minds already.
GT6 could've expanded to PS4. I don't understand what they did to keep the game locked on PS3 system forever. The Last of Us was supposed to be the swan song of PS3 but Naughty Dog still ported the game and found bigger success on the PS4 than it did for former.
TLoU is narrative heavy. GT6 isn't.
I don't really see the connection here. Polyphony having to go back and port the entirety of GT6 is an undertaking that ND would have most likely not bothered to do.
I doubt the financial backing would have even been worth it.
Whatever the risk was. It would've been worth it. Gran Turismo sells on its name alone but Sony let GT fans wait for four years before Gran Turismo Sports was released. That is damn too long even considering Gran Turismo's PS3's long cycle of development. The mindshare of Gran Turismo for this gen is in critical conditions. Forza and other racing sims caught up or to put it accurately, Gran Turismo has gone down because of its long absence in the generation of PS4.
If Polyphony is still sane, they should know they can't keep resting on their laurels. The prestige remains but they are in trouble of losing sales and mindshare as the racing sim genre continues to shrink in market size. They do not even have have other IPs to fall back into if Gran Turismo flops so they have to be smart or evolved the game to continue or reclaim their dominance in the racing sim genre.
This is still great though. Sony have reasons to be more critical to Polyphony's autonomy. Their sales underperformance and naivete of this current generation should lit a fire under their butts so they won't make the same mistakes again.