It does seem to be happening - at least in mobile app stores.
There's some recent analysis that demonstrates how, despite a huge updraft in the quantity of apps released, the aggregate count of reviews and downloads remains static.
In other words, there are now many more apps. But not many (or really any?) more users
Take a look at p40 / figure 12 of "WRITING CODE VS. SHIPPING CODE: PRODUCTIVITY EFFECTS ACROSS GENERATIONS OF AI CODING TOOLS" (https://www.nber.org/system/files/working_papers/w35275/w352...)
Their analysis is on pg42-43
> they should be clear about why this time is different to the entire history of the computer industry so far
I can't prove the pie is fixed, but nor can you prove the pie is infinite.
Maybe this comes close to sounding patronising, but I think the key thing people miss, when talking about economic growth of software is, money has to come from somewhere. Someone has to give it to you. So it you want to keep growing, you need someone who isn't paying for software, to start. Who are these people, how much money do they have, and what other costs are you competing against?