I am pretty confident my next phone will be an Apple device. I was an Android fan, purchased all google/nexus devices starting with the G1. I had problems with many of those devices. I have switched to Samsung, but the amount of garbage on the phone still annoys me. Therefore, it is time to try iOS.
What I really like about OnePlus is their software. It's hands down the best Android version ever created. Love their additions to vanilla OS.
- https://www.xda-developers.com/oneplus-6-bootloader-protecti...
- https://www.xda-developers.com/two-critical-oneplus-33t-boot...
While OxygenOS is smooth and not bloated and their phones are cheaper than other flagships (in some markets at least), their security record isn't the best.
And they had other security issues, both with their phones and servers. I'm sure you can find more info with a quick search.
OnePlus makes good phones, but this thread is about Android security... and they don't have the best record.