Understanding OnePlus's phone lineup in 2019

There are a lot of different phones, and they aren't all available everywhere. It wasn't that long ago that OnePlus had the simplest phone lineup of any company. It had a single phone that it updated and replaced with a new version every 6 months. It even did so with a predictable cadence, alternating between full-generation updates and subtle "T" refreshes. It was also really great about releasing the same phone around the world, so it didn't matter where you lived — you could get basically t...