The 2nd Amendment did not apply to the states until two years ago and the right to keep and bear arms is not "effectively dead" even in those states that do not have a RKBA clause in their constitution.
The point of the 2A is not to grand the right to keep and bear arms, but as a last ditch measure to keep the government from infringing upon what the people who wrote the constitution clearly viewed as an extremely important civil right. The government is no more justified in infringing upon that right whether or not the 2A exists or not.
That's an ideal. It does not really apply to the real world. If the SCOTUS interprets the constitution as not having a RKBA, and will not stop any type of firearm restriction from being passed, then there's little any individual can do other than simply accept it. That will almost certainly be the case under a repeal situation. Even if the 2nd isn't repealed, the courts still have significant latitude to interpret the law, although they will be probably forced to give some degree of firearm freedom. What we saw in the last two years is the SCOTUS giving a stronger interpretation that use to have.
I don't understand why supposedly left-wing "progressives" want to stomp on civil rights in this area. Supporting restrictions on civilian gun ownership is a right-wing view.
Progressivism is not necessary libertarianism. A lot of it implies forcing people to make sacrifices or restricting certain behaviors if it means it benefits the common good. Tobacco laws, traffic and car safety laws, worker safety laws, etc., all fall under the category of progressivism. The label is flexible and changes from era to era however. Lately, probably due to the extreme concentration of liberals into large cities, gun rights is rapidly disappearing from being associated with progressivism and will probably become a purely right wing one.