As far as I know, the US is the only country in the world that has surrounded their constitution with a "don't touch, just reinterpret" veil of protection.
I live in a country where changing the constitution happens every once in a while, and often is necessary to solve (often idiotic) problems arising from misformulation, blatant anachronism or other forms of legal mismatches with the real world. Such changes are subject to major scrutiny (e.g. 2/3 majority required to pass), and definitely not easy to pass through parliament. Making this impossible seems excessively conservative, and somehow assumes the constitution is special and can never be made better.
Is there a mechanism (aside from amendments, which, well, can only amend) that allow legislators to update the single most important legal text of the US? Various amendments can also become outdated in their formulation or at least contraproductive because the interpretation changed. It seems to me the judiciary power has too much wiggle room to change the meaning of passed laws without those changes going through the elected channels (i.e. parliament).