Why is it that the Netcraft survey may not be an accurate way of determining the number of apache web servers on the internet?

The Netcraft survey may not accurately reflect the number of Apache web servers on the internet due to its sampling method, which primarily relies on actively probing a subset of websites rather than a comprehensive analysis of all web servers. Additionally, the survey may miss servers that do not respond to its requests or those that use techniques to obscure their server type. Furthermore, many websites use content delivery networks (CDNs) or reverse proxies that can mask the underlying server technology, leading to underreporting of Apache usage.