Why does unreal spawn a ParticleEventManager in a basic project?

If I create a new empty c++ project, I notice that quite a lot gets spawned when I click play, even if I haven’t added anything to the scene, like a ParticleEventManager and a GameNetworkManager. Are these hard-coded into the engine? Is there a way to turn them off, since I assume they’re consuming cycles whether I use them or not?

The easiest way I found to disable that was to in my DefaultEngine.ini under category ‘[/Script/Engine.Engine]’ set ‘ParticleEventManagerClassPath=’, without the single quotes.
This prevents that actor from being spawned.