While it was true that the glass of the screen had cracked due to a fall, the phone had operated just fine for many months since. The Genius told me it was likely a display issue while I told him it's much more likely a software issue. The Genius gave me the unfortunate advice of restarting the phone by holding down the power button and the lower volume button. The phone restarted, with the Apple logo in full brightness but would turn black when it came to logging in. Pity, since my password is too long to type it in without visual aide.
The Genius told me that to repair the display was $200+. I scoffed at the price and told him it's not the display, and it was unacceptable as I planned on buying the iPhone 12 next month. The manager came by and made it clear there's no room to budge on the price. I resigned and left the device with them.
When I was called in to pick up my phone, they told me that replacing the display did not work, so now my option was either to upgrade or to buy another iPhone 7 for $400+. I told them that's unacceptable and that it's clear it's not the hardware. I told them I am immersed in their ecosystem and I would easily spent another $2000 this year and to cut me a break. They told me, take it or leave it.
I took the phone back and started making my way home. Descending into the metro, I walked past an ill-lit part of the platform. I looked at my phone again and realized I could faintly make out the log in screen. I typed in my password, logged in, went to control center and raised the brightness back up. Perfect. Now, even if I lower the brightness to its lowest setting, it works as normal.
Not only is Apple's moves to cut out 3rd party repairs egregious, their own solutions and staff are rife with incompetence and their offer to you once you've immersed yourself into their ecosystem is, "Money now or go away".
I am not buying the iPhone 12 and my next machine will run Linux.