Why Does My 2 years old iPhone 6s,SE Battery Die So Fast? [att and MS]

AT&T Community Forums
Care Code: 205.4 error message by dahlia61:...
me:scare me to the death after i post my opinions about att email new updating functions then when i re-login my email account got "That user ID doesnt seem to work here. Sign in with a different ID.  Care Code: 205.4" so i thought i were punished and spent lots time to solve it in the end i guessed https://currently.att.yahoo.com(AT&T Yahoo Mail version?) just terminated on 1/21/2021 permanently. i tried to check my file about "att email clients would request to buy new equipment before xx/xx/2022..." then found the file in my HD was stolen which i just reviewed couple days ago. we were att client for quite long time until fed up many troubles then switch to 2 other providers. Should we back to att client again or dump long years emails or buy new att equip?
ps (att community forums)obviously every one here got the same error in different dates. so im not sure what is the trigger.
however i solved it by visit www.att.com sign in then select email and sign in again. which also request verification code.
....however half hour ago when i tried to login att.com it shut down so i tried to find any other solution
Yahoo email Care Code: 205.4 by captainninja:Just got off the phone with ATT.  This is a known issue; they have some kind of outage they are working on it and to give them 24 hours to resolve.  Our sbcglobal account is also affected, but can get through to the email by signing in via att.com instead of Yahoo.
Me:im afraid 24 hrs is not enough time to solve if the problems caused by email new functions. myself was software project leader knowing the simple the best, stable is the most important. Since MS developed Onedrive i already pointed out it is a diaster because my data files are stolen frequently.
my best advice for at&t designer team stay away MS file system either create a space for user to keep clients attached documents, photos, receipts... if att believe that is clients want; or recover the old version so clients can continue use.
ps my above opinion for some reason not showing. this earlier morning not just att.yahoo email got problem, my mouse also weird behaviours so i tourned off notebook till late evening but still quite difficult. while MS auto updated caused many new weird processors in task manager.
when i tried to delete email showing previous renter agent personal photo, i found it will kill agent sent my emails and those new functions as "photos, documents, subsriptions, deals ,receipts, travel" got too complex link and MS file index with emails attachments.
I can tell it definitely would fail.

PS just found my mouse in 360 my library can smoothly scroll up and down, also can click left button without weird behaviour as before MS auto updated this earlier morning but in udn and AT&T email, Community Forums and earlier in my reading 小说：青帝作者：荆柯守 are not especially Firefox top tool bar.

I would say 360 is high quality maintain well.

PS today morning my spouse supposed go shopping earlier to avoid virus infected but i told him i didn't sleep because email problems caused me in hyper motion then he told me he likes outlook free email because simple while at&t is too complex, gmail also got bad reputations. And i mentioned facebook for my one china opinions ridiculous blockaded me twice... I also pointed out i didn't use outlook because i don't trust MS and he didn't maintain any important emails(i have to do the jobs) so he can't really know whether outlook is good enough. however i would give it try if at&t can't in time solve problems. In the past we were charged penalty and interest because didn't receive att emails when att took weeks to solve this and that problems.

1/22/2021 conversation with relatives:

me: 抱歉 我的手機電池可能快要壞了才買兩年 正忙著檢察各種可能原因 在這裡換電池要 $50 新的也不過$150左右 換新電池沒有原廠的電池好 很煩惱

sis: i-phone6s。IOS15 已不支援使用
me:不確定是ios15 造成問題 小銀幕手機 ES （就是我現在使用）因只作為打電話專用 也在我試這試那取消部份功能後改善不少 但6S 僅當日改善次日又不行 不過6s 我們早已終止電話付費 不知是否這個引起 （6s最後買的）早期購買 tablet 也因低價電話費品質極差故終止付費也出現電池問題 但到今年仍可當相機使用(it is a miracle!) 現在可能考慮在筆電用 LINE
哎 不行在筆電使用 line 因為無法輸入中文  只好用小銀幕ES 手機啦
ps i can't understand why LINE in notepad didn't apply cell phone 輸入中文 app? how about china WEchat?
ps  i like 360 my library ...just wish can combine with traditional chinese typing app.
--i think i really need to learn 汉语拼音字母表 Laaa. my sis learnt fast and in old time she as businessman looking for china products so represented us to contact our relatives in china a lot. if our taiwan relatives also use WeChat then i definitely learn 汉语拼音 fast.

Quite regret when we lived in previous house i brought mom attended nearby 希林学校(chinese from china built organization) activities that period time i didn't think of to learn 汉语拼音字母 from classmates but busy to learn china's songs.

ps 4/20/21 today my spouse told me att got sued news because maliciously made clients cell phone Battery Die fast. no wonder my cell phone SE recently battery in quite good shape, not like before that battery die very quickly, and didn't see error message as "not support" screen  popped up again. I should happy to hear it but worry what if fall down or shut down att.yahoo email.

my spouse told me he would verify whether he did read i sent email  "020421--the psycho stole power supply and mouse not knowing whatelse yet " on Feb or not. And it did happen att then att.yahoo.com didn't in time delivery emails but delays days. for that we were forced to pay credit card/utility companies delay payment punishments. but delay over months that seemed not happen in the past..