I didn't factor the ISS fate into what I proffered. I was basing that on human behavior I have witnessed over my lifetime.
I point to major network coverage because it is symptomatic. Yes, it can help drive public interest but in an era of media fragmentation where networks are desperate for every viewer, it is highly indicative of public interest. That is likely to increase until Artemis IV completes its mission.
You're right that 10 million isn't "a small number," but if that is from online viewership then the potential market would be global, not just in the U.S. That places the market size in the billions.
I don't doubt that there is core of people whose interest in the space program will endure; I just think the average person is myopic and easily distracted. We've seen this happen previously and I don't believe the species has dramatically changed its innate behavior in the last half-century. For instance, the restaurant server mentioned in the OP also told us there were customers who actually complained when the TVs were switched from the Masters golf tournament to splashdown coverage.
Also, I encounter so much willful ignorance, stupidity, selfishness and lack of appreciation every time I leave the house that it doesn't give me any indication people are suddenly attuned to the life of the mind. Go read the reddit megathread on splashdown coverage. What remaining factotum of faith I had in people was pretty much shattered in November 2024.
I also think oncoming climate change is going to stress civilization in a way not fully anticipated yet. Combined with growing wealth disparities and how AI might be changing employment scenarios (and the resulting downstream effects), it might become harder to hold together a space program than currently realized.
I understand your enthusiasm and respect it. I am just jaded.