As most viral illnesses, yes it has generally gotten slightly less lethal. It’s not super clear whether this is mostly due to existing resistances built up from past infections/vaccines or due to mutations. That said, it is definitely not a joke and still kills people in vulnerable groups every day, in addition to likely being the cause of permanent organ damage in many infection cases that don’t result in death.

In fact, going back to the initial question, these changes over time could make it even more important for sick people to fully isolate, as the infectivity is higher.