[Pyxl101]

You misunderstand the meaning of "militia". The term militia as used in the constitution essentially means the entire populace, all people capable of fighting. The US Supreme Court in Columbia v. Heller examines the meaning of the words and phrases in the Second Amendment: https://www.law.cornell.edu/supct/html/07-290.ZO.html

An armed populace was viewed as crucial during the founding of the US because when able-bodied men of a nation are trained in arms and organized, they are better able to resist tyranny. The modern era demonstrates that this is still relevant: see Iraq, Ukraine, Syria, etc. There's a great documentary on Netflix that shows, from footage on the ground, what transpired while the Ukraine crisis unfolded. Ukraine's local self-defense forces gave the protesters a foothold that eventually took down the unjust government (at least, that's the narrative - I'm only remarking on their effectiveness as a fighting force, and their relevance to political change).