Does this break links and lead to link rot? Other StackExchange sites don't seem to have the page rank of StackOverflow. It also makes it harder to restrict sea

Does this break links and lead to link rot? Other StackExchange sites don't seem to have the page rank of StackOverflow. It also makes it harder to restrict searches to a particular site when questions are spread across multiple sites inconsistently depending on what year they were asked.