For what it's worth, it's not exactly the same COVID. I'm no scientist, but as I understand, the majority of COVID viruses are less dangerous than the 2020 batch. Millions of people died that year. If that were still the case, we'd be seeing a lot more death.
Since this is an experience you had with a single person, here's my take on it: That interaction was one moment to you, but the other person had a lifetime to develop that mindset.
I don't know who you're talking about, or what their ailment is, but they've probably been discussing it online for a while, and have probably gotten a LOT of medical recommendations. Some of them, great advice from people with experience, the rest are crystal suppositories.
They probably just wanted to stick to the topic at hand or vent about an experience without having to sift through a bunch of people telling them about meds they've already researched or why they should go vegan.