I'm generalizing....
.....And that is basically what the Peruta case was about,,,,and it did reach SCOTUS,,,,, and they denied to hear it.
Not really - the Peruta case was about licensing to carry a weapon when one leaves leave home. A more fundamental issue is licensing/permitting to even own a weapon in the first place. Somewhat different animals,and one could argue that the former should be argued before the latter.
One could also argue that the courts conservatives have been waiting for the right case to clarify the legal doctrine by which any of those cases should be reviewed --> strict scrutiny. Once that doctine is in place (or frankly any single coherent doctrine - but preferably strict scrutiny), then we may see SCOTUS take on more 2A cases IMHO.
The level of scrutiny will have a profound impact on the burden of proof required to defend whether a particular licensing scheme is constitutional. And, so far, there is really no coherent and singular level of scrutiny used in examining 2A cases.
If strict scrutiny is adopted as the doctine for 2A cases, then the burden of proof as to why a "fundamental right" is being constrained shifts squarely to the gov't, In that case, a NY, IL or MA licensing law would need to defensible that there is a compelling state interest behind the policy, and the law or regulation is
narrowly tailored to achieve its result.
Intermediate scrutiny dilutes things a bit - that a law/policy serve an important government objective, and an must be substantially related to achieving the objective. It is be an easier tasks defend many (even most) licensing schemes using this doctrine, if a law/policy is framed serving the important objective of public safety, and the law/policy is substantially related to that end.
Rational basis is the lowest level of scrutiny - essentially where the courts pretty much just defer to the gov't just because the gov't sez so ... even if it has not demonstrated or proven a rational basis for a law/policy.
And, indeed, we've seen courts across the US use any of these three tests (and more often than not intermediate scrutiny and rational basis - rarely has strict scrutiny been applied to a 2A challenge to date). And that doctrinal incoherence is a fundamental problem when challenging licensing schemes like NY, IL or MA. If a court uses a rational basis test, they will basically accept the government position ... because the government says so. The blanket deference to "public safety" claims. Likewise, intermediate scrutiny makes the government work a bit harder to justify its stance, but intermediate scrutiny makes it fairly easy to defend such policies simply beause a firearms regulation can be generally/substantially tied to a government objective (public safety/crime control).
Strict scrutiny, however, is not a magic formula for waving away firearms regulations. That doctine, however, is an essential element if SCOTUS is really to frame 2A as a fundamental individual right. Heller and McDonalds went a long way in framing 2A as an individual right. The question as to it being a fundamental right - akin to 1A protections - is the next major battle.