HL is still the best for IL-2 But you have to check at different times for servers to have people playing, one problem is that there are 3 different versions 4.13, HSFX and the SAS mod so that makes the amount of people playing even smaller between servers.
This is probably true for people who are casually looking to join in online servers and missions etc. The IL-2 community is a lot smaller than it once was, but there is still a significant number of players taking part in various activities that do not appear in HL.
Though it is shown on Hyperlobby, the excellent SAS server is mainly accessed direct by members, therefore showing no players online in H/L for instance