Why did my apps not transfer on my new phone

You have asked us to guess everything about your particular situation.

Apps are downloaded from the App Store (cloud) to your new iPhone. This happens when your iPhone is well charged, on a strong Wi-Fi signal, and not overly busy doing other things.

Some older Apps may not be compatible with a new phone. You can redownload the apps that are compatible by going to the App in the App Store and clicking on the small cloud icon.