The "slow editor/loading times" and "giant bundles" is just technical, so should be "easy" to fix!
The hard bit I think is the "spaghetti no-code" problem that I've seen in nearly all visual-type programing environments. Just because it's no code, all of the logic still needs to exist somewhere. When we code we can break it apart in many ways, and how you break things apart and abstract things depends on the system.
But no-code tools are fixed, and you only have one way to divide up the logic. In Bubble's case, it means there's a "design" section with UI and data-binding, and a "workflow" section with all of the actions that happen: UI interactions and business logic are smooshed in together. You end up with thousands of boxes indicating actions, in a giant list. You can kind of group them, and you can colourize them - but everything is held together by convention. A single logical flow can require many UI elements, and tracking that logical flow through the various unrelated boxes is... spaghetti!
In Structure and Interpretation of Computer Programs it says "Every powerful language has three mechanisms for [combining simple ideas to form more complex ideas]:
* primitive expressions, which represent the simplest entities the language is concerned with,
* means of combination, by which compound elements are built from simpler ones, and
* means of abstraction, by which compound elements can be named and manipulated as units."
Most of the no-code tools seem to miss (or have a too simple version of) the final mechanism: "means of abstraction". So the entire system is built of combinations, that are poorly tied together.