I get what you're saying as far as "practical" purposes go. It's also arguable that (in the spirit of your argument) the outer reaches of the Milky Way are also

I get what you're saying as far as "practical" purposes go. It's also arguable that (in the spirit of your argument) the outer reaches of the Milky Way are also irrelvant. However, when people sit around and think about the possibilities of alien life, or rather - the probability that alien life exists outside of Earth, it's *100%* relevant to consider galaxies outside our own.