I think you're too quick at making assumptions which are not correct unfortunately. Let's recap:
> there's no selective pressure for it to become less lethal.
> If people take measures to prevent spread of a disease that’s literally selective pressure.
How trying to slow down its spread can "force" it to become less lethal?
The only possible answer is that lower lethality gives it more time to spread around right?
It turns out Covid has a long incubation period, in fact plenty to use the host to infect other people.
Tl;dr: Given the length of the incubation period a less lethal virus would not gain much in terms of its ability to spread. That's the thesis I'm hearing.
> there's no selective pressure for it to become less lethal.
> If people take measures to prevent spread of a disease that’s literally selective pressure.
How trying to slow down its spread can "force" it to become less lethal?
The only possible answer is that lower lethality gives it more time to spread around right?
It turns out Covid has a long incubation period, in fact plenty to use the host to infect other people.
Tl;dr: Given the length of the incubation period a less lethal virus would not gain much in terms of its ability to spread. That's the thesis I'm hearing.