Xcode is an Integrated Development Environment. One of various IDEs available.
Swift, C, Objective C, C++, and Objective C++, are programming languages supported within Xcode.
Other IDEs can have differing selections of supported languages.
Each programming language has different strengths and weaknesses, and often different abstractions and frameworks and foci.
You can write a simple and buggy and crash-prone app in any language, or can create a sophisticated and elegant app.
It’ll take longer and involve more source code to write an app in a lower-level language or in assembler, as compared with creating the same app a higher-level language with available abstractions and better frameworks, too. This irrespective of the IDE used.
Though an IDE does make handling the ever-larger wads of source code easier.
That Xcode, some other IDE, or command line tools, was used, is not directly relevant to the quality of the created app.
In carpentry, there are various different hammers and power hammers available, carpenters will routinely use several different hammers on one project, and a particular type of hammer chosen does not have a direct outcome on the finished project. But having a belt-fed power hammer makes certain types of nailing work much more efficient. Other sorts, not so much. Carpenters will discuss their preferred tools, too.