Say what you will, but AMD's RDNA 3 architecture doesn't bring anything significantly new to the midrange sector. All the stuff you mention is fine, and ultimately should mean higher performance per clock... but what will the RX 7600 deliver in the end over an RX 6650 XT? That's the real question, and the one you're ignoring.
Because tweaked cache sizes, doubling the ALUs, etc. is what AMD says RDNA 3 provides. On paper, it all sounds fine. In practice, though? RX 6950 XT has 5,120 ALUs that provide ~23 teraflops of compute, while RX 7900 XT has 5376 streaming processors and 10,752 ALUs that provide a theoretical ~52 teraflops of compute. It also has a 320-bit memory interface and 20GB compared to 256-bit and 16GB. How much faster does it end up being?
According to all of my benchmarks: 19% at 4K, 18% at 1440p, and 15% at 1080p. That's 126% more theoretical compute for up to 20% more performance.
So when you crunch all the numbers and see a potential 32 CUs in the 7600 providing ~21 teraflops of theoretical compute, and RX 6650 XT with 32 CUs and ~11 teraflops, I think it's entirely valid to question whether it's actually going to be any faster in practice.
Let's assume RX 7600 ends up being ~30% faster than the RX 6600. RX 6650 XT is already 25% faster than the RX 6600. So we'd be looking at 5% more performance, for 15% more money, going by US prices. Or if you prefer, RX 6650 XT cards cost $360 CAD to $390 CAD for the Asus Dual, ASRock Challenger D OC, Sapphire Pulse, MSI Mech 2X OC, and XFX Speedster SWFT 210 Core. If the base model RX 7600 cards are $440 to $450 CAD for similar models (Sapphire Pulse and MSI Mech 2X), that's still about 15% more than the RX 6650 XT. The nicer models like a Sapphire Nitro+ or Asus Strix will probably cost over $500 CAD, keeping the same price difference as the base models.