It does, so it’s not like all that functionality is inaccessible from ROS2. But you would need to learn a reasonable amount about packages in ROS1 as well to know how to use them properly. Thus exclusively focusing on ROS2 would leave you without significant functionality.
Personally, if I were starting now, I would start with ROS1 and learn about what ROS2 can do without learning how to do it until I encountered something that could be done in ROS2 but not ROS1 (real time control, for example). Then I would learn the ROS2 stuff necessary for that. Viewing ROS1 and ROS2 as an exclusive-or relationship is not a good approach.