What examples do you have in mind?
I would describe philosophy as about assembling a 'toolbox' of ideas, discussed here: (Why) is this negative outlook on the concept of philosophy misguided? In philosophy we aim to distinguish between our cognitive and cultural biases, and accurate assessments of things.
It doesn't sound like you've thought very hard about the meaning of 'subjective'. We were discussing recently how attractiveness seems to have a subjective aspect unique to a given person, but that also we often mostly agree, and sometimes almost everyone agrees: Is physical attractiveness subjective? We know genes and culture are involved, so this shouldn't be surprising. Trying to seperate everything into 'totally objective' and 'entirely subjective' is a false dichotomy. A useful term is 'intersubjective' as a third option, like money is not objective because it's an invention made by agreement, but neither is it purely subjective, if you write your own banknotes they won't suddenly become valuable.
Philosophy emerged to try and go beyond just winning over an audience with points, towards 'Socratic dialogue' or mutual commitment to find the best answer.
For instance, by identifying formal and informal fallacies, quickly identifying bad types of argument. Logic, good reasoning, well structured argument, aren't purely subjective or we couldn't have science. When we try to avoid assumptions, biases, & so on, we aim to work less from our own personal view, and more from the view anyone else in our position would share with us, regardless of experiences, mood etc. That is, we use tools to pick out or develop what is intersubjective, from our subjective experiences.
An example of a good piece of philosophy is Hume's Is-Ought distinction. Another is the Private Language Argument. These are tools for the toolbox, to help 'shew the fly out of the bottle', and avoid talking at crosspurposes. Both of these also reflect in different ways on what subjective and objective mean. Examining definitions, checking we agree on them, and that we are using them coherently, is another big task of philosophy. The necessity of this aspect of philosophy to science when the experimental programme fails, discussed here: How much philosophy should a physicist know?