Bill S. Preston, Esq. and Ted "Theodore" Logan are absolutely iconic characters. While the concept of the underachieving high school student certainly wasn't born with Bill and Ted, the duo belongs in the pantheon of great iterations of the trope. Even after the two left high school, Bill and Ted have largely not changed. The pair are completely spaced out most of the time. The two might be total slackers, but Keanu Reeves would ask that you not call them stoners.
We never see Bill or Ted make use of any foreign substances in the movies, but that hasn't stopped the duo from being labeled as stoners over the years. It's certainly true that Bill and Ted seem to be incredibly relaxed a lot of the time, as if they could be high, but Keanu Reeves recently made it clear to AP that the friends just have a very "nice outlook" on the world. According to Reeves...
I'd like to get one thing straight. Bill and Ted are not stoners. You know, they have a nice outlook. They like people -- their friendship.
It seems pretty clear that Bill and Ted aren't stoners. At no point in the movies do they ever get high and there isn't even an indication that they ever have. It's certainly true in the first film that they're more interested in playing music (badly) then studying in school, but that's not exactly a unique perspective that requires drugs. They are certainly laid back guys with a unique outlook. I mean, when they both get murdered by a pair of robot duplicates of themselves they don't even get that upset. They're just sort of bummed out. One can only hope that all of us would approach life in this way.
In the end, the fact that Bill and Ted are not chemically enhanced, and rather just seem to love people and life very naturally is probably a large part of why the characters became so popular. They just never let anything get them down. They're almost always very positive about everything. When they reach an obstacle, they always find a way to deal with it and move forward. Even if that means needing to play Battleship against the physical incarnation of Death.
Even decades later we see that's still the case. Bill and Ted Face the Music will see our "not stoner" friends coming to terms with the fact that they have never fulfilled the destiny they were told they would achieve back in the first movie. They have become dads and the film will also follow Bill and Ted's daughters, who it appears have largely embraced their fathers' perspective on life.
Bill and Ted Face the Music arrives in some movie theaters and on VOD platforms Friday, August 28.