Scaling to large projects is difficult even when you fully code things. There's an art to learning how to manage it and design things so that you can take them as far as you want to go.
The JavaScript (and now TypeScript) support in Construct is partly there so that if you are willing to code, you can use it to help scale your project further, or do advanced things beyond the capabilities of the built-in plugins and behaviors. For example you could write a custom pathfinding algorithm, running in a web worker for multithreading, and tweak it to match the specific needs of your game. You don't need to use the addon SDK either, so you can bypass all the configuration stuff you need to set up event sheet features, and just custom code something for your project. Then you can still write things nicely with modules and re-use that code across different projects, too.
So if you want scalability, or to do more advanced stuff than the plugins/behaviors provide, that's part of the reason it's there! You can usually also use event sheets for custom logic too of course - it just takes more work. Construct has always been designed with the philosophy that the built-in stuff covers common cases, but is flexible enough to adapt to specialist needs, or if you need to do something really customized and advanced, then there's capable coding features too.