Can't say I really agree with that. IB is simply "Different". It's hard to compare apples to oranges. AP and IB classes are "Advanced" classes in a subject matter. The IB program however, is advanced classes in ALL subject matters. But it also includes social and community involvement and development; as well as learning on a global basis. E.g. Instead of localized classes, it includes world literature, world history, etc.
Because it's a very strict program; 30,000+ high schools and only 800+ have the IB program in the USA, it requires IB certified teachers. These teachers make additional money. Thus, many teachers and teachers unions don't like the program. The tests, exams, scoring, etc. isn't done at the local level, so curving grades and other potential improprieties aren't as prominent. Almost 1700 universities recognize the IB Diploma. (Students also receive their local state approved diploma of course).
Having spent more than 20 years in the military, something very similar I noticed were the DODDS (Department of Defense Dependent Schools); also a number of "International Schools" around the world where children of "Foreign Nationals and Workers" could send their kids to school when stationed overseas. DODDS and the international schools had standards and requirements that were recognized and standardized across platforms. This way kids would not be at a disadvantage when they got back to their home country and back to a traditional local school. Most times, the kids who attended DODDS and International schools, did much better and were ahead of those in local Public/Private schools. The IB program is similar in that regard. It has a set of standards, curriculum, etc. that is standard throughout the world. More than 140 countries have IB schools.
But it isn't uncommon for some kids to think they are better, "Academically", than some others because they are in the IB program. That attitude isn't promoted by the organization or the local school, but it obviously happens. In my state, Wyoming, there are only 2 public and 1 private high school in the entire state that offers the IB diploma program. If you're in the IB Program, it's natural to feel a bit different. When my kids started in 9th grade, our middle schools were 7,8,9th grade. High School was 10,11,12th. But if you were in the IB program, you started at the high school in 9th grade. That automatically moved you to "High School" a year sooner than your peers and friends you grew up with since elementary school. But most kids; especially those who go the full course and receive the IB diploma, do not think of themselves any better than anyone else. My son played 6 years of football, 3 on varsity. 10 years of soccer, 3 on varsity. He played on the same team as the kids he grew up with, lived in the neighborhoods, hung out with on weekends, etc. but they weren't in the IB program. So maybe your son's friend was a snob; but most aren't.