TSMC can't change physics, though. It's full of marketing fluff, most importantly they can only find ways to pack transistors bit denser but that still will mean more transistors means more power use. So we could see 6090 bigger and another 200W+ power use and new PSU needed again, just to squeeze a bit more performance. I'm very realistic about it, consumers won't like that.
I just posted my 4090 on eBay last night, for about the same price I bought it for 3y ago (1750). Within minutes I had 4 offers and then it sold less than 5 minutes after posting it... I didn't expect that so had to scramble to order 5090 (2050 quid) and new PSU (Corsair 1kW). The buyer is a Chinese person, with 10y on eBay and hundreds of positive comments, including by buying GPUs - it will likely instantly go to China, get vram upgrade to 48gb and end up in their AI farms. They didn't even ask for proof of purchase and warranty. Reminds me of the times I sold to them cards they used for mining back in the days, never any issues, they are usually best type of buyer. Also, I should've posted for bigger price for sure, as in Chinese grey market they flip for over 3k easily. And the whole upgrade just to get more vRam so I can use much bigger context window for writing. xD nothing to do with gaming even, as 4090 never held me back.