For the first point, that is, even if you are a novice, if you want to develop an App alone or with several small partners, you need to consider the code architecture, class design, and smaller programming best practices and skills when writing code. These things are often not done by an architect or a more experienced programmer (even in many mature companies), and you need to control them yourself. This leads to a problem. An experienced and solid programmer may write an App with good structure, easy expansion, stability and high efficiency, but a novice or a programmer who never cares about these may write an App with extremely chaotic code, resulting in poor application stability and even poor interface, which will affect the user experience. So I think everyone is an architect when writing an App. Whether you can do this role well has a great influence on the final result.
The second point is ignored by many programmers. App interacts with users constantly, and users are very sensitive to details such as interface design, interaction design, function design and even color, animation and font size. So I think that in most cases, to write an excellent App, programmers need a certain aesthetic ability and understanding of the product. Of course, you can say that these things are decided in advance by products, designers and interaction designers, and programmers only need to be responsible for their implementation. However, how programmers restore these implementations, what kind of code they use, what kind of API they use, and what kind of open source libraries they use are all manifestations of programmers' comprehensive ability. I have seen very elegant applications. For a few apps, I will use "silky" to describe their user experience. I have also seen many big companies' fully functional, conservative and well-behaved apps. However, what I see most is the blunt interface, which makes people have no impulse to touch at all. Can you say that programmers are not responsible for this situation?