Lots of great replies here already. My 2 cents...

If you play classical, you will encounter the power chord shape quite often in the form of a "dyad" (2-note harmony). It may not be root-fifth but it will be there. Try this...

play 6th fret of the A string and 8th fret of the D string (the power chord)

-then-

play 6th fret of the A string and 7th fret of the D string (dominant tri-tone)

-then-

play the 5th fret of the A string and the 8th fret of the D string (inverted 1-3 dyad)

See how that resolves? We are using the power chord shape as a dyad. You will encounter this all of the time in classical. It will be how you generate harmonic movement.

Also, for any music using overdrive/distortion including modern country or any large band situation (including classical), dropping some chord tones out (or spreading them between instruments), will prevent the overall sound from becoming too muddy.

So even if power chords feel like a waste of time for your genre choices, they are building blocks for lots of other things.

(video of Bach being played by 4 classical guitars...I believe I hear some 1-5 dyads/power chords in there!)

https://www.youtube.com/watch?v=VE_nnpsIEAw