Everything dies at some point. Even the universe probably will. As for Bitcoin, it's currently technologically relevant, but we honestly can't know right now for how long it's going to be this way.
There's also a certain limit on the price of Bitcoin at any given time. The global economy can be monetized, and Bitcoin cannot be worth more than all of the goods and services in the world. Of course, the global economy can grow, but it does so pretty slowly.
It's okay not to set a strict limit on how high the BTC price will reach, but there is a ceiling for that. Moreover, having a target in mind can be helpful to decide when one is actually ready to use/spend Bitcoin, and not just hodl it.
I can not disagree with you and I afford to lose money with my belief and investment in Bitcoin. I know of risk and accept it with my investment decision and existing position but I really disagree with any people who are over worry about risk of quantum computers or something too far in future like what will happen in and after 2140.
I believe Bitcoin won't die after 2140 year but I don't have such concern because I will not be alive in a next 100 years. It is too far in future for me to worry about.