Should you upgrade? This depends if you can run what you have until February next year.
Why February? By February, the new stuff is out, all quirks on the Intel H610 / B660 / H670 / W680 / Z690 motherboards will have been ironed out, DDR5 will have dropped in price ($30 instead of $100 extra), and 13th gen will by then be thoroughly tested.
Meanwhile on the AMD side, AM5 will have been out for 3-6 months by then, along with the A620 / B650 / X670 boards. While not all bugs will be fixed by then, most initial quirks will be ironed out. So I would say, unless you don’t mind the rough ride this autumn as the new generations get broken in, february is the month to aim for.
I personally am more interested in the AMD system, because if AM4 is any indication I can possibly keep the same motherboard for at least five years, only swapping CPU and upgrading RAM.
That said… If your machine is on your last legs, and you are fine with no upgrades to CPU and memory, a 5950X build with 64 GB of memory today makes a TON of sense, too. One word of caution though, make sure you have the cooling for a 5900X or 5950X, ITX boxes especially are pretty limited unfortunately.
At the same time, pairing a 5950 with an RX 6600 is like going to the gym and work only torso and legs for 6 months. You can’t lift worth shit but MAN can you jump if you do that. High end CPU deserves a high end GPU.
With that in mind, I would recommend this build for you if you plan on upgrading today. If you want extreme high-end, get a 5950X and 6700 XT or better.
Better yet, throw in a PSU and a Case in there and you can maybe sell your old system, or at least donate it to a family member, non profit org or something.