Most of TSMC's capacity is allocated years ahead of time. They're contractually obligated to supply AMD wafers at a predetermined price and volume.
Also, GPUs are pretty good at mining Ethereum. ASICs are only about 2x as efficient, many miners would rather have the security of knowing they can always sell their GPUs to gamers if it all comes crashing down.
Also, GPUs are pretty good at mining Ethereum. ASICs are only about 2x as efficient, many miners would rather have the security of knowing they can always sell their GPUs to gamers if it all comes crashing down.