My point is that whether the US constitution is flawed is a separate argument to whether having laws enshrined in a single document is preferable to basing laws on a collection of statutes and judgements. Both systems will inevitably produce flawed laws because they are designed by flawed people who are subject to their own norms and prejudices and the mores of their time. So arguing that constitutions are bad because the US one originally protected slavery and disenfranchised women is a straw man, entirely irrelevant. Arguing that constitutions are bad because the second amendment enables Americans to shoot each other en masse and the political makeup of the country means that changing it is effectively impossible is relevant and valid.
The whole idea of democracy as a viable means of governance relies on people being politically active and advocating for themselves. This is also why it's such a difficult system to maintain. So I would disagree with you that there are fundamental flaws in the rule of law. There are flawed laws, but there are also procedures in place to change them. The rule of law is the only thing that keeps a democracy afloat. We need to be able to trust that the majority of our fellow citizens will respect the laws, even if they don't like them. Not liking a law isn't in itself a reason to disregard it, though disregarding laws as a means of political protest to draw attention to how abusive they are is something I respect. It's led to the Civil Rights Act, increased women's rights, and the end of the draft, among others. But the only reason that breaking laws as a political protest works to change things is because we normally follow the rule of law. So overall, the principle of having encoded laws that most everyone who lives in the country consents to follow, whether they are good laws or bad ones, is sound policy and essential for democracy.
But, being aware of other peoples' perspectives and trying to see familiar things through different eyes is something everyone should strive for. Social media is great for this. Movements like Black Lives Matter, which is almost entirely social media driven, are great for raising awareness and getting dialogues going, even if a lot of that dialogue is argument. At least people are becoming aware of a different point of view. That's also irrelevant to the constitution argument, though
