I paid for my marriage license in Nevada, Hawaii and all states recognizes it as valid.
I passed and was awarded my motorcycle license in WA state- Hawaii recognizes it as do all states.
I was tested and earned my first drivers license in CA- all states recognize it.
I now have one of those Yellow star Hawaii drivers License, meaning "they" know who I am,
with a paper trail a mile long, recognized and valid everywhere.
But a CCW License isn't recognized and valid in all states.
Why is that?

The "why" is rhetorical, I'm sure.
Some states' leaders and lawmakers believe in the individual rights and freedoms protected by the Bill of Rights in the Constitution, so they are good with minimal restrictions to be able to carry in public.
Other states think guns are the devil's invention and should be banned 100%. Short of that, as long as nobody but LE are allowed to carry in public, it makes them "feel" safer.
Reciprocity is a problem because some of the more restrictive states don't trust the CCW permits from states with less restrictive carry rules. Part of that problem stems from there being no nationally recognized minimal training or testing standards, unlike how drivers' get their licenses. Marriage licenses are similar. As long as the state issuing the license follows minimum guidelines (properly signed and witnessed licenses and officiated by someone authorized to perform marriages), every state accepts them.
So, the simplest solution would be for the Congress to pass a reciprocity law that specifies the minimum guidelines for issuing a permit, which may include a background check, classroom training to learn the law, and live fire training. If you are between 25-71, your Hawaii driver's license is good for 8 years. Minimum expiration periods will also have to be addressed for CCW permits so anti-gun states don't set a horribly short renewal timeframe.
Until there's a national standard to set these minimum criteria, we're stuck with each state doing their own thing.