"a small portion"? Seriously?
Looks like most have a sleep/charging issue, many if not most wifi/lte issues, tons have bad screens,
all have the annoying "beauty filter" on the front camera + there is no real speed gain,
just some bionic marketing BS.
Looks to me like the worst launch for an iPhone ever.
Sounds like someone is a disgruntled customer.
There is after all a 100% complete fix for this situation.
Return that phone and purchase something else. There is no reason you should live with that levels of frustration with a product. Let it go.
Apple is Apple and will continue being Apple and "hoping" or "demanding" change will get you and your feels absolutely nowhere.
Return or sell the phone. Have some closure on it. Find something else. Move on from it.
If the frustrations go away completely then you know that stress came from Apple. If the same stress stays, repeat and sell and purchase one more time if there is another phone option for you. If the stress of issues stays then you may have to look inward and accept that it is "me" and understand either A. companies will never create a perfect quality product I accept that. or B. I will never be able to be happy with a product because my expectations are too high and therefor I will continually be let down.
Should you have standards? Absolutely
Then you have to have a level of understanding if that particular level of standards is attainable from the "thing" you are comparing them to.
Even with people. If you expect a particular person to say things a certain way or do things a certain way just automatically, you will be let down immediately. And that's ok, but know it is your expectations that are getting hurt, not the other person or company or thing purposely hurting you.
Either way, hope you find whatever it is you are looking for.
F*** Stress.