Bitcoin is complicated enough that there's no real good elevator pitch. However to just plant a seed and let them research themselves I say something like:

"Bitcoin is just money that isn't controlled by the government. You work your entire life for pieces of paper the government can make for free. Bitcoin is just a fair alternative. Give it a bit of research."

Then sometimes I'll point them to Fidelity or Blackrock publications if they're a tradfi person, since those are trusted names with fairly good papers on why Bitcoin is the best monetary asset.