Someday everyone alive will die, does it stop being true if you live to 20?
If I lived to 20 and literally nobody in the world had died, then yes, that would be a rational conclusion.
Look, I don't expect to convince you of anything, that's fine. You can look at trends and history and draw your own conclusions. Personally though, I've watched the march of technology first hand, I've seen how this works and I see where there's room for advancement. The last major paradigm shift was when we moved to multi core processors, but that kind of shift can happen again. For example, CPUs are still 2 dimensional, if they can solve the heat dissipation there's plenty of room for growth. Also we're still transmitting signals via electricity, but there's research being put into optical computers transmitting data via photons. My point being, this isn't the only viable architecture, and we will continue to develop technologies that are currently not even imagined yet.