I can't think of a reason it'd be impossible to build a no-code app that scales as well as code, and I don't have evidence that Bubble has failed.
If felt like there was a missing level of abstraction - everything was too intertwined. Making changes to anything becomes harrowing once the app becomes large - it was slow, and you don't know which UI elements are being accessed by any blocks - so it's really easy to break things without realizing. And the undo system gives you no visual clue as to what is being undo-d if it was in a different view. It was the most fragile system I've worked on.
However, many of those issues could be fixed, improved, or redesigned. If you were doing "regular" use-case stuff it was... fun! Our designer could get in and implement/test things really easily.
My gut feeling is that there could be system that scales well - but the escape hatches need to be reliable when you hit the edges.