Matt Mercer syndrome was never real.
Any time someone gets into a hobby because of a specific property they expect it to be like that thing.
Communicating with your players and giving them reasonable expectations for an upcoming campaign, whether it's D&D or Lancer, or anything... that's on you, not random D&D content creators you think are setting unrealistic expectations.
Speaking from 20 years of experience. Baldur's Gate and Neverwinter Nights were what people expected my campaigns to be like.