Joel has an older Samsung Galaxy S5 and it's just fine. But he isn't sure if he should wipe it and start over. Is that necessary like it is with a PC every once in awhile? Leo says that it's good housekeeping for a computer. It puts it back to the day it first came and gets rid of all the "cruft" he doesn't need. With a phone, it's a bigger challenge because of music, pictures, text messages, etc. Music and Pictures can be backed up to the cloud, or a PC, pretty easily. Text messages, though, is another challenge. The chatroom suggests this app from the Google Play Store.
Leo recommends turning on his Samsung and Google account and enabling "Backup and Reset". He could also root the phone and get rid of that Samsung Touchwiz overlay. Then he could install a better launcher like Nova Launcher.