After having owned an iPhone for the last 10 years, I finally encountered a problem that left my iPhone 8 Plus dead. Thankfully, it happened in the first three months of having the 8 Plus and it was covered under warranty.
Every night I usually put my iPhone on the charger so I have a 100% battery every morning. Last Thursday, I woke up and found my iPhone was off. I tried to turn it on using the wake button and it didn't go on. I followed the steps in this support article to try and get my iPhone to turn on without going into DFU mode and erasing the whole thing.
For some reason, I couldn't get the Apple Store app to make a reservation with an Apple Genius. It kept trying to take me to Apple Support.
So, I went to the Ala Moana Center Apple Store and checked in and made a reservation. It took me about an hour from the time the store opened at 9:30 a.m. to get a "new" iPhone 8 Plus. I spent the rest of the day restoring my backup from iCloud. All of my apps downloaded by the evening. I have 214 apps.
All in all, it was fairly painless to fix the problem. I don't even know exactly what the problem was with my original 8 Plus. But, I don't really have to know. I just needed a phone because I was expecting a call that day.