The problem with philosophy in terms of understanding the bigger questions in life is that advanced physics (edit: and neuroscience, chemistry, math/stats, etc) has answered many questions that were previously in the realm of philosophy, and you can't really understand what's possible in reality / what constraints there are on abstract philosophy without understanding advanced physics and science.
Of course the problem with advanced physics is that it takes so much time and effort to learn and understand thoroughly that you often end up as a not great communicator to the average person.
Or, to be cheeky: physics aims to take the largest and most complicated concepts in the universe and explain them in the simplest possible language, and philosophy is the opposite.
Philosophers literally invented formal logic to help them answer questions. Yes they are trying to answer questions and constrain the possible answer space where they can't.
I would argue that it absolutely applies to both existentialism and epistemology. Epistemologists frequently concern themselves with questions about the limits of human knowledge and understanding without actually going there themselves.
Sure, but at a fundamental level philosophers are not just sitting there asking questions with no purpose. They're still seeking new understanding and information which is a form of answering questions.
Much like how martial arts is no longer as useful for self defence in a world with handguns, but instead makes for very good exercise and social connections, and is just fun.
Except that a key difference is that no one gives out PhDs for martial arts. Yes you can get a black belt, signalling that you are as skilled as the top tier martial artists (I assume, I don't do martial arts), but you cannot write a peer reviewed paper and get a PhD on karate because that would require learning something new about it and publishing it.
Philosophy in how the common person relates to it may just be as a mental kata that helps to improve their cognition and emotional regulation, but philosophy as a profession and academic discipline is still very much concerned with trying to answer questions and find ways of constraining the infinite to relevant possible answers.
The point I'm making is that philosophers are trying to answer questions and if they weren't they wouldn't be getting PhDs, since a PhD is not given for just knowing a lot about Philosophy, but for discovering something new in the field.