"Investors are putting pressure, change the version number now!!!"
I'm quite sad about the S-curve hitting us hard in the transformers. For a short period, we had the excitement of "ooh if GPT-3.5 is so good, GPT-4 is going to be amazing! ooh GPT-4 has sparks of AGI!" But now we're back to version inflation for inconsequential gains.
Because it will take thousands of underpaid researchers random searching through solution space to get to the next improvement, not 2-3 companies pressed to monetize and enshittify their product before money runs out. That and winning more hardware lotteries.