It was used to directly create and remove SVG elements from the DOM, simplifying the updateView function.

It allowed the game to handle multiple user inputs simultaneously, which was not possible with map and filter alone.

It eliminated the dependency on an external, mutable state object by managing state transformations purely within the stream, making the logic self-contained.

It improved rendering performance by batching DOM updates instead of applying them one by one.

It provided the main game loop by replacing the interval(10) observable, which was causing performance issues.