Baldur's Gate 3 is already there. It's over 120GB and IIRC PS5 games only use up to triple layer. There was no disc release.
The current Gran Turismo is around 140GB. I think it has a disc, but it'll only have like half the game on it.
Final Fantasy XIV is around 200GB now, and they're talking about dropping PS4 support because drive capacity is going to be too low during the patch cycle for the next expansion.
Also, median US internet is over 100Mb/s now, so downloading a game is faster than installing it from a BluRay reader. And then you don't have to get up and change discs to change games...
Regardless, most console owners buy their games online. Otherwise there would be more games than Funko Pops at GameStop. They also have frequent sales, unlike retailers.
Hey just a correction, there was indeed a physical release of BG3 on PS5. It was released straight from Larian and came on 2 discs, dual-layer 100GB to be exact. Xbox Series as well, but it came on 4 discs due to capacity limits.
Your point stands, though. Games have grown so huge that downloading them isn't a hassle for most, but disc definitely is or has maxed out. That's not to mention how long it takes to install stuff, especially on PS5!