When I was digging into this stuff a few years ago, what appeared to matter most was transmission and immune evasion. Whether or not the host died was irrelevant if the virus was spreading before the host showed any symptoms. Which is what we saw in 2020 and 2021. High transmission rates and high mortality rates.
However, viruses evolve over time and our immune systems can adapt to new threats over time. With COVID, there's an inverse relationship with transmission and immune evasion. As people's immune systems were able to recognize the virus, the variants that evolved to avoided (or delay) an immune response were the successful ones. Because of that inverse relationship those variants were also less successful at transmission.
Other factors like the ability to damage the lungs, damage to the sense of smell, etc. are essentially irrelevant if they don't improve a virus's ability to replicate and transmit. If they aren't being used then they will disappear over time.
Which appears to be what we are seeing now. A virus that has evolved to survive long enough in humans to replicate and transmit while evolution has culled the features that don't improve survival.
Well this is interesting. Some background:
https://www.troyhunt.com/experimenting-with-stealer-logs-in-have-i-been-pwned/
You wouldn't happen to have some malware on your computer or logged into an account from a compromised computer?