First, the prerequisites:
1- Unlocked bootloader with Magisk and TWRP (you can use temporary TWRP if you please). If you don't know what is that, take a look at the XDA threads about it, it's easy. Please don't ask about "how to unlock bootloader" or "how to install Magisk".
2- Debloater (Terminal Emulator) Magisk module. Download it from Magisk Manager.
3- Any Terminal Emulator app.
4- import-debloat.txt config file. Download it here
5. Backup :P (yeah, this module doesn't change anything in /system and can be reverted at any time, but backups are always welcome)
6. Magisk Mount script. Download it from here
Magisk mount is needed to "reinstall" system apps by deleting the dummy folders from Magisk partition if something breaks.
If you have everything handy it should be a matter of few seconds to debloat.
Let's deal with useless system apps, temeletry, some shitty apps. According from the @Tomatot- thread:
-You'll get more privacy: I've removed Qualcomm telemetry, OnePlus telemetry as well as some Google Telemetry (but you can't expect too much as long as you use gapps)
-You'll get better battery life: less apps running in the background, less wakelocks, less services communicating with servers to send telemetry.
-You'll get better performance: for the same reasons. Don't expect a huge difference as our phone is very smooth already.
-The feeling of having a clean device. And this has no price.
AntHalService^=/system/app/AntHalService AutoRegistration^=/system/app/AutoRegistration BasicDreams^=/system/app/BasicDreams BookmarkProvider^=/system/app/BookmarkProvider BTtestmode^=/system/app/BTtestmode PrintService^=/system/app/BuiltInPrintService card^=/system/app/card EasterEgg^=/system/app/EasterEgg EgineeringMode^=/system/app/EngineeringMode EngSpecialTest^=/system/app/EngSpecialTest GooglePrint^=/system/app/GooglePrintRecommendationService GoogleTTS^=/system/app/GoogleTTS LogKitSdService^=/system/app/LogKitSdService NetflixActivation^=/system/app/Netflix_Activation NetflixStub^=/system/app/Netflix_Stub NFCTestMode^=/system/app/NFCTestMode OEMTCMA^=/system/app/oem_tcma OEMAutoTestServer^=/system/app/OemAutoTestServer OEMLogKit^=/system/app/OEMLogKit OnePlusBugReport^=/system/app/OPBugReportLite OnePlusCommonLogTool^=/system/app/OPCommonLogTool OPSesAuthentication^=/system/app/OPSesAuthentication PartnerBoorkmarksProvider^=/system/app/PartnerBookmarksProvider PhotosOnline^=/system/app/PhotosOnline PlayAutoInstallConfig^=/system/app/PlayAutoInstallConfig QdcmFF^=/system/app/QdcmFF RFTuner^=/system/app/RFTuner SensorTestTool^=/system/app/SensorTestTool SoterService^=/system/app/SoterService Stk^=/system/app/Stk Talkback^=/system/app/talkback Traceur^=/system/app/Traceur UIMRemoteClient^=/system/app/uimremoteclient Video^=/system/app/Videos WallpaperBackup^=/system/app/WallpaperBackup WAPICertManage^=/system/app/WapiCertManage WIFIRFTestApk^=/system/app/WifiRfTestApk GoogleFeedback^=/system/priv-app/GoogleFeedback OnePlusCellBroadcastReceiver^=/system/priv-app/OPCellBroadcastReceiver Tag^=/system/priv-app/Tag USBDrivers^=/system/etc/usb_drivers.iso Reserve^=/system/reserve RFToolkit^=/vendor/app/Rftoolkit AmazonShittyApps^=/vendor/etc/apps Account^=/system/app/Account OPBackup^=/system/app/Backup BackupRestoreRemoteService^=/system/app/BackupRestoreRemoteService CarrierDefaultApp^=/system/app/CarrierDefaultApp CTSShimPrebuilt^=/system/app/CtsShimPrebuilt GoogleDrive^=/system/app/Drive GoogleDuo^=/system/app/Duo GooglePay^=/system/app/GooglePay HTMLViewer^=/system/app/HTMLViewer GooglePlayMusic^=/system/app/Music2 NVBackupUI^=/system/app/NVBackupUI OnePlusPush^=/system/app/OPPush YouTube^=/system/app/YouTube BackupRestoreConfirmation^=/system/priv-app/BackupRestoreConfirmation CallLogBackup^=/system/priv-app/CallLogBackup CTSShimPrivPrebuilt^=/system/priv-app/CtsShimPrivPrebuilt GoogleRestore^=/system/priv-app/GoogleRestore GoogleBackupTransport^=/system/priv-app/GoogleBackupTransport GoogleOneTimeInitializer^=/system/priv-app/GoogleOneTimeInitializer ManagedPrivisioning^=/system/priv-app/ManagedProvisioning OnePlusWizard^=/system/priv-app/OnePlusWizard OPAppLocker^=/system/priv-app/OPAppLocker OnePlusDeviceManager^=/system/priv-app/OPDeviceManager OnePlusDeviceManagerProvider^=/system/priv-app/OPDeviceManagerProvider SharedStorageBackup^=/system/priv-app/SharedStorageBackup
1. Copy the import-debloat.txt config file to the folder /data/cache in the root. (you can copy it by a root explorer or reboot into recovery and copy it by TWRP file explorer)
2. Install the Debloater (Terminal Emulator) Magisk module using the Magisk Manager.
3. Open the terminal emulator app
> Type 'su' and press enter
> Grant root permissions
> Type debloat and press enter.
4. You will see the options to debloat in various categories which are self explanatory. As we have the config file which has a predefined app list to de-bloat stored in /data/cache folder in root already. Type 'i' which says import config and press enter 2 times.
5. Reboot 2 times and you're done most probably if nothing breaks.
Ta-dah! Fully debloated OOS. To keep the debloat after update the ROM, just reflash Magisk and you're fine. You don't need to do the procedure every update.
Read from here if something breaks (from @Sreekant)
If it breaks the system or causes boot-loop which shouldn't be the case as I'm using the OP7 9.5.8 and everything is fine, but well, **** happens. Don't worry! It's pretty easy to reinstall all of them in one click by TWRP.
Did you download the Magisk Mount script which I asked to earlier? If yes, just flash it with TWRP and the magisk will be mounted and accessible in TWRP file explorer. If you didn't download the script earlier, Just adb sideload it in recovery.
After mounting the Magisk in TWRP > Click on Advanced and go to file explorer.
Then delete the app folder of the system app you've uninstalled in /Magisk/terminal_debloater/system/app (/sbin/.core/img/terminal_debloater/system/app) or /Magisk/terminal_debloater/system/priv-app (/sbin/.core/img/terminal_debloater/system/priv-app) then that should undo it.
Feel free to give any feedback about the script.
Special thanks to:
@Tomatot- (the apps list and some explanations are from his thread)
@Sreekantt (the thread base and original idea from debloat for Poco F1)
@topjohnwu (Magisk developer)
The Debloater (terminal) team