Python’s urllib2 (now urllib.request) started out in the year 2000 [0].
.NET’s WebRequest was available in .NET Framework 1.1 in 2003 [1].
But since then, Microsoft noticed the issues with WebRequest and came up with HttpClient in 2012. It has some issues and footguns, like those related to HttpClient lifetime, but it’s a solid library. On the other hand, the requests library for Python started in 2011 [2], but the stdlib library hasn’t seen many improvements.