Think about it this way, these are the teams who have made the playoffs every year of the last five seasons:
San Antonio
Dallas Mavericks
Denver Nuggets
Cleveland Cavaliers
Los Angeles Lakers
That's it. Even the Jazz don't make the cut. This is over the last half-decade.
Five teams. That means only 16% of the league's teams have made the NBA playoffs consecutively the last five seasons.
Of those I've listed, Cleveland is probably not going to keep their streak alive and Denver is in serious jeopardy of losing theirs.
That shows you just how inconsistent the NBA is and frankly, I think it's solely because franchises are consistently blowing their rosters up and going through coaches like they're toilet paper.