Why use IHttpClientFactory instead of new HttpClient() in .NET

// ======================================================================
// Q: Why IHttpClientFactory instead of new HttpClient()?
//
// - new HttpClient() on every call: socket exhaustion (sockets stay in
//   TIME_WAIT).
// - One static HttpClient forever: it does not see DNS changes.
// - IHttpClientFactory / typed clients: handler pooling and recycling, central
//   configuration (base address, headers), resilience (Q11), logging.
// ======================================================================

builder.Services.AddHttpClient<IErpClient, ErpClient>(c => c.BaseAddress = new(erpUrl))
                .AddStandardResilienceHandler();