The Constitution may be a good Constitution or at least a good enough Constitution to be legitimate. That doesn't mean it's a perfect Constitution. For example, it may be that it's too hard to amend the Constitution, that somehow the rules governing amendments should be changed to make them easier, but that isn't about what the Constitution means. That's about whether the meaning of the Constitution is good enough and should be changed, so, therefore, that is not a challenge to originalism itself. Most of the debate about whether originalism will keep up with changing social norms assumes that the text of the Constitution itself is something that governs changing constitutional norms, rather than the text of the Constitution is largely structural, and it allocates power to various other branches of government to adjust to changing in constitutional norms, like, for example, a popularly inactive Congress or a popularly inactive state legislatures. It's popularly inactive legislatures, through their legislation, empowered by a Constitution, that responds to changing social norms, not the Constitution itself. Originalism can provide for change, but because the application to particular situations is always going to be different. You take the original meaning of the text and then you develop implementing doctrines to apply it to new circumstances. Those implementing doctrines, being constitutional constructions themselves, can change as circumstances change. That's the true living Constitution. It's living constitutional law to implement a fixed constitutional text.