Love2D can be cross-platform. Balatro was made in Love2D and was released on PS4, PS5, Xbox One, Xbox Series X, Switch, Desktop, iOS, and Android.
That doesn't mean it's well-supported or easy to fully support those other platforms. I'm struggling with getting iOS native functions working with Love2D in iOS, for example, although Balatro proved that it's definitely possible. The basic game (the game as it works on my PC) is working on my iPhone just fine, though, and wasn't too difficult to get up and running. I also have an APK working on a cheap Android phone I got.
Like everything the answer is... it depends on what you're looking for.
What does cross-platform mean to you? Just MacOS/Windows/Linux? Web? Consoles? Android? iOS? Blackberry?
Godot comes pretty close to a batteries included cross-platform engine that handles 2D/3D.
JS engines can likely be ported (with varying degrees of effort as PWAs, electron/tauri, etc) to most systems as well - look into Phaser though its intended use is 2D.
Probably Monogame, a C# framework that supports Windows, MacOS, Linux, Android, iOS, iPadOS, Playstation 4, Playstation 5, Xbox One and Nintendo Switch
Don't some of them have proprietary APIs under NDA? how can an open source project support them? I ask because this is one of the criticisms towards Godot when compared to Unity.
That doesn't mean it's well-supported or easy to fully support those other platforms. I'm struggling with getting iOS native functions working with Love2D in iOS, for example, although Balatro proved that it's definitely possible. The basic game (the game as it works on my PC) is working on my iPhone just fine, though, and wasn't too difficult to get up and running. I also have an APK working on a cheap Android phone I got.