Also, it's interesting to note that Buffy's strategy resembled what she'd end up doing to close the Hellmouth itself, again against overwhelming forces: empower everybody, and then blow everything up.
Angel's failure to do the same at the end of his series might, metacontextually, mean somethingsomething. Pound by pound, I think Angel's crew at the end kicked more ass, but all the bruhahaha on "Champions" clouded the issue.
Hmm, perhaps Angel (for all I love the series) is a cautionary tale of what happens when you can't figure out a way to outgrow the myth/pattern/prophecy you are trapped into, while Buffy (for all the problems it had, specially in its last season) showed what happens you do say "Fuck this noise about The One. I'm the one... with an army of slayers."
In that light, it's cool that the story stopped there, because that's the point. You don't kill the monsters until you think outside the parameters of the story, effectively ending it.
So you smile to the big hole in the ground that was your nightmare of a town, and go on with your life.