What's left tends to be not so much "common sense" as "the stuff that supports the status quo, whatever it is", because human psychology tends to have a strong pro-status quo bias.
Individual problems like:
* how do you distribute a resource that isn't evenly distributed on the planet?
* what, if anything, do you do about the variation in abilities across different people?
* what, if anything do you as various people in a community start to gain (and wield) more power than others?
* how do you address free riders?
There are so many more. The answers to these questions are not "right" and "wrong". They're not even of the form "this is best compromise we could come up with". The answers someone feels are best will be highly dependent on their values, which we know vary significantly. You can't just wish away the differences between what an eco-socialist would say about these things and an anarcho-capitalist. They are real differences, representing fundamentally different ideas about the nature of humanity, the role of government, the purpose of society and much more.
And as I said above, people have thought about these questions for centuries, and their answers generally fall into distinct groups (even if they are not all identical). We call these "ideologies".
The difficult problems haven't changed much in hundreds or thousands of years. What happens when "people who are more interested in reasoning through difficult problems" have spent a few centuries actually doing this?
Yep, ideologies. That is, semi-consistent sets of beliefs, assumptions and values that explain why things are the way they are, how they ought to be different and (sometimes) how to go about making the changes. I know it can seem hard to believe, but it turns out that even when extraordinarily smart people think about difficult problems, they don't all converge on the same answers.
If you want to start over from scratch ever generation, be my guest. In your rejection of ideology, you're really just throwing away the work done by our ancestors.