This is and was my very first iPhone. As I decided to give it a try after over 10 years with Android. I have never had such a slow and steady failure like this before. Ever since mid July I would completely lose cellular service for 3 or more hours every week. It then happened every couple of days and the it happened every day, so I had to use my S9 Plus as a backup. No amount of updates would work, iTunes restore and DFU would come back with errors and factory resetting inside ios lead to this. Warranty expired in June and I dont have applecare. I looked up what this image meant and it came up as baseband failure, a hardware issue. I wish you guys well but I don't think I am coming back to iphone anytime soon.
Doesn’t look dead.
This is a bad baseband. This prevents the device from activating. Here is why
During activation, your device sends out its unique identifiers to apple, and after it is checked if it is locked or not, you get back either an activation ticket, or an activation lock screen. (Random fun fact, this server is called Albert, say hi to Albert)
So as you can guess, when the baseband fails, you lose your IMEI. Your device sends out its unique identifiers but it's missing its IMEI. This makes Albert very sad, and he doesn't know what to do. Therefore you get this. It says you just need an update but doing as it says doesn't help.
Basically, you get left with an expensive paperweight.