load() just loads things as soon as it's called, so it can be used if you're making an open-world game and don't want the whole map loaded into ram at once, or if you switch from one level to another maybe you want to load some new assets and unload the previous ones to save memory. If you're not worried about that you can just use preload() yeah.

In GDScript, there exists the global preload method. It loads resources as early as possible to front-load the "loading" operations and avoid loading resources while in the middle of performance-sensitive code.

Its counterpart, the load method, loads a resource only when it reaches the load statement. That is, it will load a resource in-place which can cause slowdowns when it occurs in the middle of sensitive processes. The load() function is also an alias for ResourceLoader.load(path) which is accessible to all scripting languages.

From the docs: https://docs.godotengine.org/en/stable/tutorials/best_practices/logic_preferences.html

For a personal project, I'm using load() because I don't know which file I'm supposed to load when the scene starts. Also, said file can change during game runtime.

In my case, I'm changing textures. With the game paused, the player can change some stuff, like the character's hair. I don't need to preload all of them, and maybe a preloaded one might not be the one that should actually be loaded in the end.