“Militia” at the time were just citizens who had a duty to appear armed when called. Their weapons were their own.
Now, one might argue that we no longer have any need for militias, and therefore there is no need for anyone to keep and bear arms. Nevertheless, in my state at least, every able bodied person between the ages of 17 and 64 is subject to being called to militia service by the governor or the adjutant general. The statutes make a distinction between the “organized militia” (national guard) and the “unorganized militia” (everybody else of the proper ages who is not a minister or disabled). If you’re not in the former, you’re automatically in the latter.
Yes, potential enemies are a long way off, geographically. But they were even more distant in relative terms when the Constitution was written.
Seems to me an armed citizenry was exactly what the drafters of the Constitution had in mind.