Process engineers&material scientists seem more cautious. I'm sure shrinking goes but gains are smaller from each generation.
TSMC 3nm Process is something like 250 MTr/mm² and single digit performance increase and 15-30% power efficiency increase compared to older prosess.
Performance increases from generation to generation used to be much faster. TSMC's N16 to N7 was still doubling or almost doubling performance and price/performance over the long term. N5 to N3 is just barely single digits.
Every fab generation is more expensive than in the past. Soon every GIGAFAB costs $30 billion while technology risk increaseses.
The first one built will get cheaper to run every year - it will pay for itself by the time a second company even tries to compete. The first person to the "final" node will have a natural, insurmountable monopoly.
You could extract rent basically forever after that point.
Consider other mature technology, like the internal combustion engine. ICEs have been improved continuously, though the changes have become marginal as the technology matured. However, if research and improvements on ICEs ends entirely it's not because the technology has been fully explored but because they're obsoleted by electric cars.
Not sure that is really true based on the data. Remember, Moore's law says the number of transistors in an IC doubles every two years, which doesnt necessarily mean a doubling of performance. For a while in the 90's, performance was also doubling every two years, but that was largely due to frequency scaling.
https://upload.wikimedia.org/wikipedia/commons/0/00/Moore%27...
A lot of the new processes have not had the same cost reductions. Also, some increase in transistor count is due to physically larger chips. Also, you have “Epyc Rome” on that graph, which actually isn’t a single chip but uses chiplets.