Actually, no, it has problems but you still need a way to mobilize.
Both the 1907 National Guard Act (written by Teddy Roosevelt to address what he felt were some problems with restrictions on his ability to "conduct foreign policy" by sending Militia units overseas, standing them up as nationalized forces for as long as he needed them) and the draft itself have constitutional problems. Those need to be addressed.
But in the nuclear age, we have to be able to react quickly, or die by failing to do so. This all needs to be dealt with, within the framework of the Founding and Original Intent.
If it is felt that Original Intent of the Framers was inadequate to the current threat environment, the deficiencies, if any are found in the Constitution, would have to be dealt with by amendment.
If we get to the point where we need to “mobilize” today’s youth, we are already doomed.