Since I work with small businesses, I see this culture shock often. Larger corporations might manage culture and be purposeful about it. In small companies it just...exists.
First I suggest you decide your goal. Do you raise the question here because you want to get projects done without stressing out, or because you are feeling compelled to "help" the organization “improve” the culture?
If the former, then use the good advice from other responses in this stream: look to the vision/mission of the company (if one even exists in writing!), and use whatever skills you already own to prioritize what's on your plate, making best guesses about criteria.
If the latter, and want to build a more productive/less conflicted environment, start with Curiosity. As a direct report to the CEO, you are likely positioned to be an influencer in this company. You might start by sharing your experience and asking, "is this environment intentional, or is this simply what's in place because we've never thought about it?" My experience in smaller companies is that the way they do things is based on what’s “easiest” or on precedent, not necessarily best practice. By being curious (not judgmental) you can open up a conversation w/ the CEO and the leadership team.
Come from an Appreciative point of view, to honor what's in place, e.g. What's good about our current process/culture? How does it serve us to have "everything be a priority?" Then move a conversation of Possibility, e.g. “if we were reinventing our culture, what might we do differently?” Engage them in a Stop-Start-More conversation: What do we want/need to Stop doing that gets in our way? What do we want/need to Start doing that would help us be more productive/creative/etc? and What do we need to do More of/more often to support our goals?
In that process of conversation and curiosity, you can learn if people are happy w/ the culture or if they are just embedded in it and unaware that it could be different.