I dont know if you meant the statement that 'there is no such tech in existence' to be literal when you follow it with the statement that graphical achievements on the ps4 have been possible on the previous generation of consoles.
maybe you're speaking semantically and referencing dedicated tech demos rendering a single character at a time, essentially leaving that capability useless. But even then i would disagree. The ps3 "kara" tech demo doesn't look as good as the Lebron 2k14 ps4 commercial by my estimation.
Even if your point is that the improvement is marginal, i would still argue that a real-time physics engine running simultaneously with the games other process would be a leap even if a solitary tech demo was possible on the ps3.