I think everyone who has posted a table of stats for COVID-19 infection or deaths seems to do a 10 year grouping. For example here. (Used only because I was looking at that post when it occurred to me.)
However, my understanding is that physiological changes in the human body are not linear over time but tend to be more like state changes. Now, it is true these changes are not on any annual schedule either but we do have some average ages for when changes in the human body seem to occur.
Could using the 10 year grouping actually hide important implications for those trying to make personal decisions based on that data presentation?
That's exactly what I meant by "we hear about increased risk if ...". Those figures don't do much to distinguish between e.g. "these specific conditions make it more likely to be bad, and if you're old but don't have them then you're fine" and "age makes it more likely to be bad, and if you're young but have those conditions then you're fine".
Do they do anything to distinguish those possibilities? Probably. How much depends on how strongly those various conditions correlate with age. But my feeling is that e.g. cardiovascular disease is a better indication of being old than hypertension or diabetes, which I think are more likely to crop up in middle age, so the percentages feel fairly compatible with the it's-just-age hypothesis. If it were 6% for CVD and 10% for hypertension instead then I'd be more confident that there's something specifically bad about hypertension that makes COVID-19 worse.
(If I have to guess, I guess that the answer is somewhere in the middle: almost any specific health issue makes something like COVID-19 more likely to kill you, including the specific ones listed there but others too, and being older is bad because of all the ways you're likely to be less healthy if older. But who knows?)