Yes, not every app is exactly the same as some have different features that set them apart from the rest. You may have a note-taking app that is good for to-do lists and another note-taking app that allows you to export the note to a PDF. While both are essentially the same, they offer you different functionalities. In cases like this, it makes sense to keep both apps handy.
However, if you have too many redundant apps on your phone, they will eventually slow down your device. It’s always a good idea to choose which of your similar apps you like best and uninstall the others.