NBA2K is a niche Esport currently although not unpopular as a game. With the game selling millions of copies every year and more new NBA fans coming into the game every year, the betting scene is expected to grow.
Although not as popular as other Esport giants, NBA2K has a dedicated fanbase that keeps the betting scene thriving. You can always find sportsbooks offering wagers on NBA2K. NBA2K is just one game in a series of game installments. The developers keep releasing new iterations of the game which mean constant interest in the game is maintained.