Re: All risks are relative
Hmmm... it's difficult to say without knowing the likelihood of nuclear annihilation. But we can still do a Fermi estimate.
A quick search on "number us people shot by police" gets you agreement on a bit over a thousand a year, out of a total population a bit over 300 million (you wrote "citizens", but I'll consider citizen=person for this rough approximation). I was surprised at how good the agreement was amongst politically diverse sources, by the way, though I could imagine some systematic biases (I'd expect many murders by cops to go unreported and/or covered up).
I'm also saying "numbers killed by police" rather than "numbers shot". It appears the first is carefully counted. Oddly, the latter is not.
Let's say "nuclear annihilation" would kill half the US (I'm considering the risk to US people, as I assume you were as well). If the probability of nuclear annihilation in a given year is greater than 1000/150 million = about 0.0006%, you're more likely to die of nuclear annihilation than of being shot by a cop. I'd guess the actual probability of nuclear annihilation is much higher than that.
I think you may have an exaggerated sense of how commonly people are shot by cops in the US. It's indeed dramatically more common than in any other country, and is much more of a danger to Americans than (say) mass murders with assault weapons, especially if you aren't white. But even with that, they're still about 30 times less common than garden-variety firearms murders. (Again, much more common in the US than anyplace else, because Freedumb.)