It’s for gameplay programming, not engine subsystems. These events must eventually be serialized (in the serializability sense, not marshaling) and handled by a single thread for the net code to work. Basically every engine does this (or risk having unreliable networking). The goal of this (last time I looked was when it was announced) is to make it easier to have distributed networking for multiplayer games.

Also building this using c++ and LLVM will result in better performance than any blueprint system can achieve.

We can hate AI and the direction of the engine but don’t just assume the devs at Epic are dumb.