One thing I've heard multiple doctors comment on is that they are seeing more patients who were successfully managing a condition have significant declines after a bout of COVID, even a mild one. That's definitely a bit of a philosophical question trying to assign fractional responsibility but you can also side-step this to some extent by looking at it as years of life lost — e.g. if someone with a manageable heart disease where patients tend to die 10 years older dies after having COVID, that's something like a decade where they could have been around their friends and family.