There are many viruses in the world that have never been wiped out, and which I've never caught, nor have any other people I know.
The assumption that eventually SARS-CoV-2 will infect 100% of the population is a common modelling assumption. When I went looking for validation of it, I couldn't find any.
As for known dosages, as I say above, I couldn't find any information comparing dosages or cell death levels of vaccines vs actual viral infections. That would certainly be helpful to know, assuming such reports were reliable.
> When I went looking for validation of it, I couldn't find any.
It's unlikely you will find validation outside an entry-level text book for virology or epidemiology. From my understanding it's a fundamental assumption that's easy to verify: ALL viruses with a similar transmissibility profile as SARS-Cov-2 (high R0, aerosols) have become endemic, that includes e.g. seasonal influenza and all other human coronaviruses.
That's the reason seasonal influenza is not a big issue most of the time, because we already had it in the past (or a related strain) and our immune system is primed. This happens usually as children and is the reason why both young children and their parents are a lot more ill than the average.
A completely new influenza strain, however, has a similar pandemic potential as SARS-Cov-2, and one hypothesis why the 1918 influenza was so deadly for younger generations is that they likely had not encountered it before, while the older had.
In fact, if SARS-Cov-2 wouldn't go the same route as basically all similar viruses have done before, it would be a big surprise. Try to speak to an expert in the field, preferably a virologist or an epidemiologist.
Somewhat related: it's a common cognitive bias to trust self-generated knowledge more than the knowledge from others.
It's unlikely you will find validation outside an entry-level text book for virology or epidemiology
Absolutely nothing in modern epidemiology is validated against real world data as far as I can tell, and virology isn't concerned with the course of epidemics, so I doubt this very much.
The problem this assumption faces (and it is as you point out, only an assumption) is it quickly runs into definitional and logic issues. That's a very common problem in epidemiology and public health as far as I can tell. Viruses evolve, and so when talking about whether they can eventually infect the whole population you have to very carefully consider:
1. How fast they evolve.
2. How fast they spread.
3. How much evolution is required to make something a "new" virus vs an "old" virus.
4. What those evolutions do to disease which is what everyone actually cares about.
If you don't have a very firm grip on these things (and epidemiology doesn't) then you can get into a situation in which by the time a virus has infected "everyone" it's no longer the same virus at all, and thus cannot be said to have actually infected everyone. All the talk of different COVID variants is pointing in this direction. Taken to an extreme it boils down to "everyone will get infected with a virus at some point" which isn't an interesting statement.
Somewhat related: it's a common cognitive bias to trust self-generated knowledge more than the knowledge from others.
Indeed it is, and scientists are very often guilty of this: they reject any and all negative feedback that comes from people "out of field", even if it's extremely relevant to what they're doing. For example rejecting feedback by computer scientists of the form "your program does not work" because computer science isn't the same thing as epidemiology.
But in this case I actually don't trust self-generated knowledge more than the knowledge from others, because I don't claim to have any superior knowledge of epidemiology. I just know the people who claim to be experts, actually aren't.
The assumption that eventually SARS-CoV-2 will infect 100% of the population is a common modelling assumption. When I went looking for validation of it, I couldn't find any.
As for known dosages, as I say above, I couldn't find any information comparing dosages or cell death levels of vaccines vs actual viral infections. That would certainly be helpful to know, assuming such reports were reliable.