From https://www.contentpowered.com/blog/get-500-connections-linkedin/
The Value of 500+
Why is 500 a magic number when it comes to LinkedIn connections? It's the point when LinkedIn stops counting. When you visit someone with 501 connections, and someone with 30,000 connections, their profiles will both say the same thing: "500+ connections." After that, it doesn't matter, numerically.