It's hard to say. From the point of view of a beginner, it is difficult to make an app that is complicated, requires specific knowledge of outside unrelated systems like web services and/or databases, and if you need to use specific areas of the local system like the accelerometer, compass, GPS, file system, etc. If you want to make a game that requires knowledge of 3D or other advanced animation techniques, you may also need to get yourself some new math skills. That's why a lot of people prefer using no-code builders. I've recently worked on an application for an online store using Pocketfied https://pocketfied.com/. It aims to help people transform a Shopify store into a mobile app. It was so easy that the work was done in few hours. IMHO, the key point of a modern mobile app tool is simplicity.