Was it because of the decline of the popularity of the NBA or the retirement of Michael Jordan, the living legend the GOAT? I am just curious.
Since the "prior research" was requited, I would like to show.
If you go to the Wikipedia page for "Dream Team", it redirects you to a page titled 1992 United States men's Olympic basketball team, and for my money, that's your answer.
"Dream Team" is really only properly applied to the 1992 US team. It was simply in a class by itself.
Later US teams were picked based mostly on sheer playing ability, but this was the first year that pro players were allowed. So on this squad players were picked based on how big of a star they were. Pretty much everyone asked accepted, both because of how historic this team was, and because most had never had a chance to represent their country (and might not ever again).
Every squad member (except the one token college player) is now in the NBA hall of fame. Opposing players would immediately try to get autographs afterwards. One even waved to the cameras while he was guarding Magic Johnson.
I remember reading an article about the 1996 team, and how the atmosphere just wasn't the same. The only player on the squad who star-struck opponents still were trying to get autographs from at that point was Shaquile O'Neal. There was only one 40+ point blowout (the '92 team did that in 5 of 8 matches).
US Basketball along with the networks that have the broadcast rights have tried to use the term as a marketing term for the US team since then, but other than them and the announcers in their employ, I don't believe anyone else does that. Later teams are just not the same. There had really never been a team like that before or since, and probably never will be again.