That was unquestionably one intent of the 2nd, but certainly not a requirement. And we have to remember and accept that back then the average citizen 'kept and bore' exactly the same arms as King George's army (yes, even including cannons). There was no restriction on what kind, type, number of nor size of the arms an American citizen could "keep and bear". Affordability of those arms was the only restriction to the arms any American citizen could "keep and bear".
Today it would be nearly inconceivable that an armed citizenry or militia could in any way defeat our own standing army .......... unless the majority of the military chose to refuse to take a stand against their fellow citizens. Of course there would/could be a lot of guerilla fighting if it ever came to that, and a lot of citizen terrorism, but the odds of the citizenry actually defeating the military is today a weak afterthought at best. And remember there was no standing army at the time, it was only a consideration for a tyrannical gov't, or another country's army. However, since that was never the full, complete or even the main intent of the 2nd to do that, the 2nd still holds (or should hold) as much meaning today as when it was written.