In reality ddr5 will see the rice of next level apus... The problem is the risk, if people would buy those.
If someone want to have real gaming speed, they use "real" gpu. Asus did annouce amd gaming apu with 8 core cpu and nvidia 1650 gpu... It tells a lot. Ofcourse there were others using 3070 and 3080.
Making really fast expensive apu, with big gpu part would mean more defected chips, increased price and worse speed that you would get by using separate gpu. People have talked about hbm memory apus... those would be even more expensive. It does not compute economically. But ddr5 will help situation. We still don´t get very fast gaming apu, but sothing that can run low setting games at desent speed and maybe not break you bank... when the ddr5 will be cheaper aka 3 to 4 years from now.
Most possible solution would be "chiplet" design where cpu is one chiplet and gpu another in the same socket... But even that would not be cheap and as versatile as separate cpu gpu combination. So I expect about douple the current speed in integrated apu that is about as small as we have now in 4 to 5 years from now. Not much more, nor much sooner. Small uplifts in the meanwhile ofcourse.