My father died last summer aged 90. For at least 5 years previous, he was type 1 diabetic, with heart problems which meant that he would be exhausted by any type of exertion (even a fairly short walk). The only reason he lasted as long as he did was due to scientific developments of the last 20 years. At any time, in that last five years I believe Flu, a heavy cold or any other significant infection would have done for him. (I'm not even sure he would have survived a strong gust of wind).
As I mentioned in an earlier post, due to medical breakthroughs over the last few years there are now a large number of people in that category and I believe these are people at very high risk from Coronavirus.
This is exactly what I was trying to explain earlier in this thread about my father in law. Although only 80 he's basically in exactly the same boat. The next serious "thing" he gets will do him in for sure, whether it's covid-19 or flu or whatever. As a result he's mostly housebound anyway and my mum has taken to not travelling on the tube and getting his daughters to drop round food. But they have only started this routine since the coronavirus outbreak despite all his health problems and it didn't need the government to tell them what to do for them to act.