Covid is respiratory virus at its core. When you can't breathe, you of course have systemic problems throughout the body. But at its core Covid-19 is a respiratory virus. And if you have pre-existing comorbidities, as has been reported from day one, you're highly at risk. And those areas of your health that were compromised before Covid are at higher risk.
As someone with chronic respiratory illness all of my life, you're full of shit. Covid is a systemic virus at its core. It profoundly affects multiple body systems. There were hundreds of cases of asymptomatic younger patients who later turned up in hospital with blood clots, strokes and kidney failure. Then there's the "covid long haulers", of which there are thousands.
There is no risk of blood clots, kidney failure, or heart damage with chronic respiratory conditions, flu, or pneumonia. Only with covid are these additional risks.