And why the answer to that question doesn't matter.
The purpose of the 2nd Amendment ultimately lay in preservation of the "armed citizenry", a social institution of long-standing in England and its colonies by the time of the founding, and the amendment therefore ultimately supports the private ownership of small arms and light weapons, and probably also surface to air missiles, tanks, &c. For most people, though, small arms and light weapons are by far the most relevant items.
Sometimes people argue that the "well-regulated militia" of the 2nd Amendment should mean something to do with regulation of ownership, but when I've talked with them about the details, they didn't realize that militia didn't generally own or issue weapons, or that the militia relied on people to provide arms and equipment of every description, including food, uniforms, &c. Many such people treat "militia" as a synonym for "army" and so fail to appreciate the pervasiveness and importance of the armed citizenry as a complement to the government in those times. A discussion of the situation in the colonies is offered in a quite readable paper by James Lindgren: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=692421
However, I think we make a mistake on our side when we put the focus on "fighting a tyrannical government". The common law militia that the founders inherited was ultimately a large body of private people with private weapons of military capability; and it was quite capable of fighting the government; but it was also capable of other things and was ultimately organized for the common defense. A significant problem in the colonies, as Benjamin Franklin's auto-biography makes clear, was government inaction -- a failure to provide defense when it was needed. This problem was tractable and manageable, though, because the citizenry were not hampered from arming themselves and organizing for this purpose. (Franklin's autobiography discusses his efforts in concert with other citizens to establish a company of infantry and a company of artillery, which were later recognized by the governor of the Pennsylvania colony; and much later, became National Guard units.)
We should always remember that the militia was rooted in a prosocial duty, shared by citizens of all nations, of being the ultimate backstop of peace and security. The militia worked in concert with the government and were recognized by it, frequently being accorded places for training, positions in public parades, and various privileges relative to each other in acts passed by the colonial legislatures (some of which remain, in some degree, in force, as in the case of the Ancient and Honorable Artillery Company of Boston, Massachussettes). During the Revolutionary War, it is undeniable that the citizenry fought tyranny, but neither the history of the armed citizenry nor of the militia begins or ends with the Revolutionary War. They are ultimately rooted in a recognition, so important to the English and subsequently American tradition, of a complementarity of government and society.
"What about nukes" indeed. If you have a nuke or can get a nuke, you graduate to a state-level actor and are instantly unbound from the local rules and laws. It's instantly immaterial.
It would be more impactful to talk about surface to air missiles and anti-tank weapons.
"What about nukes?" is almost never a relevant or honest question when posed. My own personal interpretation is that, as written, the 2A includes ALL weapons, and that excluding nukes would require Constitutional Amendment. HOWEVER, as a practical matter, anyone with the resources to acquire a nuke, let alone maintain it, has the resources to successfully evade any laws on the subject, and the difficulty in acquiring and maintaining them is more effective than any law. If nukes were easy, someone would have tossed one at Tel Aviv by now.