Photo: Apple
If the rumours are true, you shouldn't expect a big upgrade for the base iPhone 17 model. While Apple is supposedly increasing its screen size to 6.3 inches, compared with 6.1 inches, that might be the most significant change. A new research note by GF Securities said the iPhone 17 will run on the iPhone 16's A18 chip with 8GB of RAM, despite the rest of the series being powered by the A19 processor and 12GB of RAM.
So, unless you're looking for a bigger screen, it probably won't make sense to upgrade to the iPhone 17 if you're coming from an older base model iPhone. But, as GSMArena pointed out, the lack of change might be a strategy to get you to upgrade to the more expensive models.