While TSMC is already working on 2nm Processors for 2024, they've actually begun Exploratory Studies for nodes beyond 2nm
Apple's iPhones have been riding the wave of cutting edge processors from TSMC. Apple was only one of two smartphone vendors in 2019 to use TSMC's 7nm processors. This year's iPhone's A14 chip will be manufactured by TSMC's 5nm processor.
Apple's next-gen iPad Pro is likely to powered by a 5nm processor later this year and a rumor covered yesterday points to Apple's first iMac, and perhaps one MacBook model will introduce ARM based 5nm processors.
It was reported back in December that TSMC's Senior VP of fab operations talked up 3nm processors were on schedule for full production by 2022 and you could be sure Apple will be one of TSMC's largest 3nm customers.
The smaller the processor the cooler it will run and this could possibly push mobile MacBooks to outperform x86 processors by a very wide margin.
Today, TSMC kicked off its 2nm process R&D, and is progressing in research and exploratory studies for nodes beyond 2nm, the foundry has disclosed in its annual report to shareholders. If you happen to be a Digitimes subscriber, then you'll be able to get more on this developing story.