“If being careful and cautious isn’t enough, what can anyone do?”
Very little, as you already know. If you’re worried enough, and have the capability/means, perhaps totally isolate yourself completely from others (I’m inching close to that). We can now go months without skipping a beat.
Otherwise, try to stay healthy - don’t go outside without proper clothing...dress warm. If you get into a situation where you may otherwise get sick, such as improperly dressed for cold/wet weather...don’t do it, go back and get another layer! Don’t weaken your defenses. Not much, but better than nothing.
I'm not worried. Worrying won't protect me. Apparently according to some people neither will taking precautions. Touch a table someone infected touched 2 weeks ago, according to some, is high risk. Will wearing gloves help? Well, what happens when I take them off and the gloves are infected? Someone behind me in line coughed on my jacket. Should I burn my jacket? Should I strip naked before I enter my house?
Don't think I'm ignoring the potential. I remain cautious and vigilant. Right now people are making a lot of predictions which seem to be based on worst-case scenarios. Plan for the worst, hope for the best?
When I see some of the predictions come true I'll know what further steps to take. As for now there's lots of suppositions and speculation.
Will it get worse? Yes. How much worse? It's all speculation based on rumors and scenarios.