I'm running this simple code on loop 25 times each frame

BP

C++

Hybrid (C++ & BP)

Blueprint performed the worst because it's an interpreted language and needs a virtual machine to execute, resulting in overhead during execution.

Direct C++ execution is the fastest (obviously).

Blueprint/C++ hybrid approach wasn't far behind. This is what I mostly use.

Do note that this is worst case scenario; no one is gonna be running tick on 2000 actors.

In general the performance difference (at least on PC) is super small to be even noticeable, unless you're running long tick code on many actors.