Well, there are still some indoor antennas that are better than the others. And if you buy the right model you increase the chances of getting a good reception. And if you buy a crappy one, then your chances will be far below 50%.
IMO, the best indoors are
DB2 and
SS-3000. Avoid TV-55 and the gimmicks like the "picture frame" antenna. This is a total waste of money