As Karunamon said in a sibling comment, labels facilitate reasoning. Yes, labels have their inherent risks, especially such vague labels as left and right (as applied to politics).
But we live in an age of political parties. It seems we can't do representative democracy without them, for better or worse: And given that, we need a language to talk about parties' politics in broad terms. And then we inevitably come up with various axes such as left/right, authoritarian/liberal, and so forth to describe them. So long as we remember that these are rough categories, I think it is useful and harmless. But of course, once fronts harden and the tribal impulse sets in, that important caveat may be the first to go out the window.
It's about more than just reasoning. It's about coalitions. There is one fundamental label: every vote has exactly one winner. Whether it's a law or an election, there is a single outcome. The law passes or not; one person wins the election. Either way, they need at least a plurality, if not a majority.
The more dimensions there are, the more you need to make allies to reach that bar. Nobody exactly agrees with you on all things. In order to get them to vote for your things, you need to agree to vote for their things. There's no other way to achieve it.
Policy is complex and impactful, but in the end a decision gets made. The goal is to make a decision that most people can live with. That's the best you can hope for. And you achieve that by assembling a group who support each other. That group is a real thing, regardless of the label you put on it. You're either part of that group or you're not, and you have to live with the outcome.
> Why? Why should we strive to generalize something so inherently complex and impactful as policy.
Because we (most of us, myself included) don't have the capacity to reason about the entire complex mess at once. To some extent, all thinking about the real world must be simpler than reality. This is true even of mathematical models of physical reality, even more so of mental models of politics. Yes, we should strive to improve our understanding, and I struggle with this daily, but if you remove all broad categories from consideration, leaving only the details, I for one will be lost. The usual metaphor is something about forests and trees, I believe.
I definitely agree that it needs to be simplified, but I think there has to be balance and nuance. I would think a simple left vs right is the most simplistic view one can take and thus has swung entirely too far in the direction of simplifying a view.
But we live in an age of political parties. It seems we can't do representative democracy without them, for better or worse: And given that, we need a language to talk about parties' politics in broad terms. And then we inevitably come up with various axes such as left/right, authoritarian/liberal, and so forth to describe them. So long as we remember that these are rough categories, I think it is useful and harmless. But of course, once fronts harden and the tribal impulse sets in, that important caveat may be the first to go out the window.