Obviously War of the Worlds was neither the first nor the last invasion novel written, but while the premise was quite generic for an invasion novel the particulars are so extreme and, well, alien, that it seems (to me at least) that subsequent invasion novels might have taken cues and shaken up their own formulae beyond the old Battle of Dorking-style 'foreign power invades and overrun us' narrative. I'm aware of P.G. Wodehouse's The Swoop lampooning the genre entirely in 1908, but was he just an exception?
This is a good question for r/raskliterarystudies too, you should post it there as well.