If they're not just a mirror, it seems rather strange that when a specific website disappears from Bing's index, it also disappears from DDG. In my very common

If they're not just a mirror, it seems rather strange that when a specific website disappears from Bing's index, it also disappears from DDG. In my very common sense based view of the situation, if DDG really builds it's own "index" based on a variety of sources, then why did TechDirt completely disappeared from it's search results? DDG can argue all day about how much their "local and knowledge graph" is built in-house, yada yada yada. At the end of the day, a search engine must retrieve the most relevant websites for a given query. And nothing can be more relevant to "site:xxx.xxx.xxx" than the site itself. If it doesn't appear on DDG results, then it's not indexed. And then it clearly shows that DDG is nothing but a fancy mirror to Bing search.