> The 3D it can do is kinda... "shoved" into it. It works but it wasn't designed from the ground up like other native 3D engines are.
I mean, yes and no? In that the 3D renderer is a completely separate system to the 2D renderer. But, that means that the 3D renderer... was designed from the ground up to do 3D. Unlike the other direction with Unity, where 2D support is a hack of the 3D engine.
I've been using Godot 3's 3D features for quite a while now, and obviously as a single indie developer I'm not using it for AAA features, but it's still as competent as any other renderer I've used for my use cases.
> Last I checked the editor has no advanced 3D scene editing features, and the engine itself has no basic capabilities that are needed for large open world 3D games, like being able to load tons of stuff on the fly as the player moves in a way the player doesn't notice.
You're going to have to be more specific about "advanced 3D scene editing features", as the editor is actually very good, besides which, I compose most of my 3D scenes in code. Meanwhile, Godot supports everything needed to stream assets at runtime, from multi-threading support, to async resource loaders, LOD, and so on. Granted, you have to kind of roll your own.
The main issue people bring up for large, open world 3D games (which may be a dream of most developers who've not really made a game yet, but in any engine quickly becomes a "one day" project and not something feasible for most people) is the 3D renderer itself, which doesn't have occlusion culling, but again in most realistic cases you wouldn't ever notice this (and it has been added as a feature to Godot 4 already).
For example, recently I was messing around with voxels, and recompiled the engine with a C++ module called "Voxel Tools"[^1]. This supports level streaming and movement throughout large levels without floating point errors (ie, you have a VoxelViewer node that gives the illusion of moving through a large space, while actually not moving further from the origin than you can see).
https://github.com/Zylann/godot_voxel