It's not like ChatGPT (or ChatGTP as half of people call it) is much better.
Perplexity sounds like a parody startup name from the Silicon Valley TV show. Way too complicated and unnatural.
It’s all about familiarity. Once people learn it, it’s not hard.
Perplexity is just a nonsensical word (for those unfamiliar with the concept) that is too long and hard to spell. They'd be better off just chopping it down to Lexity, or Lex, or Plexity, or Plex, etc.
(for those unfamiliar with the concept)