Arguments over gun rights aside, I don't necessarily think it is helpful to have it in the constitution. I have trouble considering the right to bear arms, if it exists, to be so important that it must be constitutionally protected while other things, like gender equality, aren't. The 2nd amendment is unique to America yet I don't think we're any less susceptible to tyranny or an overreaching government when compared against the rest of the world.
I mean, I would argue that the baked-in makeup of our nation makes us incredibly unique compared to other nations to the point that we felt the need to safeguard more extensively than most places. People aren't "Americans" in the sense that they're "Greeks." Greek people have a bond that they might attribute to the Ancient Greeks and all of their great gifts to humanity or the spiritual legacy of the Byzantine Empire or their ethnic group's struggle for liberation form Ottoman Rule ... Americans don't have a story that is based on being "a people." We purposely created a nation - one of the first of its kind in the modern world - based on ideas rather than a shared ethnic story.
Germany is called "Germany" because of how Julius Caesar described Germanic barbarians from thousands of years ago. England is called "England" because of centuries of history of the Anglo-Saxons that have shaped who they view themselves as. "America" was formed as an *idea* of what a state should be and what it should and should not be able to do to its citizens, and it's influenced our collective thought process ever since - including perhaps overextending the number of freedoms we felt that all generations from that point forth must enjoy in our country. You can soundly argue that this is outdated or should be reassessed, but Denmark doesn't need our Constitution, because ... frankly ... it's more predictable what *Danes* will do, for better (safer, more secure, less clunky acting as one) or worse (less innovative, less diverse, less dynamic).