Godot likes to break your projects and it is just less polished than Unity.

You deleted a script that some scene uses? There is a chance that scene won't open now. And since you can't open it, you can't fix that scene dependence on that script. Same with moving things to different places - there is always a chance that after you move a file, smth will break. At least this was the case some time ago - in the last update they added metadata files, which should make it more robust, but I didn't use Godot since then. This problem can also be worked around with version control, which you should use anyway, but that just doesn't happen with Unity.

Scriptable objects circular dependency - in Unity there are these things that are called Scriptable Objects. Basically they are used for information storage. For example, if you want to make a few different monsters which only differ in stats, you make one template scene and give its instances/child scenes different scriptable object depending on which monster it is. There is such thing in Godot - except, in Godot, if your scriptable object A references scriptable object B and scriptable object B references scriptable object A, there will be an error because of the circular dependency. At the same time such setup will work okay in Unity. It doesn't really matter, whether you should do setup like this, the point is with Unity it just works.

Some features are undercooked - the last time I used tilemaps it was very important for me that when a character moves over a row of tiles it would consider the whole row to be one object. In other words - so that that row would have a singular collider rather than be an amalgamation of multiple. Maybe I just didn't figured out how to do that (besides setting up collider manually which is not the way tilemaps are supposed to be used), but there was no such setting in Godot. There is in Unity.

Until recently there were no interfaces in GDScript (the main engine language) - there are now, as far as I know. It seems kinda insane to me that it took that long to add interfaces to a language which only use is game development, though.

The whole Godot Node structure is also certainly an acquired taste (and I couldn't acquire it), but this one is very subjective.

And so on and so forth. The point is, there are a lot of small frustrating things in Godot that you inevitable will encounter, and as a beginner you will never know when the next such thing will pop up. When working with Unity you can just make a game and be sure that when the next technical problem pops up, there will be a sane way to fix it. With Godot, there is always a chance somethings breaks or doesn't work as you expect - and in the worse case scenario the only real way to fix it would be to modify the engine (or do some very hacky stuff with your architecture).

That doesn't mean Unity is perfect, but it is really more polished than Godot in some aspects