Apple just announced the new iPhone 14 models this week and the question on many people's minds are if they should upgrade.
The answer depends on what situation you're currently in with you're current phone like how old is your phone?, do you need a new one?, are you willing to spend the extra money on it?, and etc.
If you have an iPhone 12 or later version of the iPhone you probably shouldn't upgrade to the iPhone 14 since there isn't any groundbreaking new features that isn't on those models. Most major features are already available on the iPhone 12 and iPhone 13 models that the iPhone 14 has. iPhone 13 users should also not upgrade to the the iPhone 14 since there aren't any major changes and the iPhone 14 uses the same A15 chip as the iPhone 14 and shares the same design.
One noticeable change however is the new size options. The iPhone 14 comes in 6.1" iPhone 14 model and 6.7" iPhone 14 Plus model size options. The mini was removed from the lineup do to the lack of sales and popularity it received from consumers.
For iPhone users with the iPhone 11 or lower, it's probably worth upgrading since you will have a lot of new features like 5G, a OLED display, larger screen size, better camera, MagSafe, and the new flat edge design introduced with the iPhone 12.
Apple does offer trade ins for users who want to upgrade to the new iPhone. You can simply trade in your old iPhone and get a subsidy that goes up to $720 depending on your iPhone model.
There's also the iPhone upgrade program where you will pay $40 - $50 every month and recover a new iPhone whenever it comes out.
To summarize, people who should upgrade to the new iPhone are users with the iPhone 11 or lower. Users with the iPhone 12 or later can hold their phones longer and wait for more exciting iPhone models coming in the future.