ChatGPT seems to me to be capable of building fully-functional apps, but just refuses to do so -- like they're mad at me or something.
For instance, I had the OpenAI ChatGPT free version (GPT 3.5) generate a simple PHP-based cronjob -- it introduced bugs, did not use PHP constants, introduced regession bugs between modifications, etc.
Yes, ChatGPT has the potential to build real, sophisticated apps. However, it requires good input and sometimes may require manual corrections to ensure desired outcomes.