Drop performance , that is sad. I have my iphone 7 for a year and i'm chargeing it somewhere between 2-4 days. Aproximatly 150 cicles for the hole year. Now my phone is 2/3 in performance and i dont think my battery has degraded so much. Maybe 3-5% at most. Thats just unfair.
I find it amazing that both battery tests were done at exactly 10:45 with exactly 80% battery. So... they what? They tested the old battery then shut down the phone, took it apart, replaced the battery, put it back together, rebooted it, then tested it again in less that 1 minute AND the battery levels happened to read the exact same? Result are a scam.
One of my iPhones which is older (iPhone 6), and definitely has a worn out battery is on iOS 10.2, unable to download the app - requires iOS 11. Some other options for testing, @iClarified?