I think I would take third parties more seriously if they ran candidates up and down the ballot in every state, instead of basically just running spoiler candidates at the top every four years.
As far as the logic of “sending a message”, as some advocates maintain, I’ll never see it that way. The last two third party candidates who won electoral votes were Strom Thurmond in 1948 and George Wallace in 1968. What kind of message did those results send that had any real lasting impact?