Hi smaratzk, welcome to Volumio. 
It simply has not been implemented. What one user considers essential, another does not. This is where the idea of plugins comes from.
Many of the plugins from Volumio 2 are undergoing the transition to Volumio 3. If the plugin was developed by a Community member, then they will need to carry out the necessary changes before it can be considered for inclusion in Volumio 3.
In the case of the ‘AutoStart’ plugin, I suggest that you look at the Volumio Plugins Collection to find details about the author and how to contact them. This might be by forum PM, plugin Github site, or a [PLUGIN] post in the Plugins category of the forum.