The camera isn’t going to be near the quality of the latest iPhones which are one of the best if not best in the smartphone market but neither is the price. Fairphone also doesn’t have the throttling issue iPhone 6 has wrt batteries, but the power it has under the hood doesn’t remotely come close either. The SoC in the FP2 (SD801) is old. The most recent 800 series (SD835) draw circles around it. I don’t know if anyone did a side by side comparison of both phones on the same moment/place because that’s a way to do some kind of vis-a-vis comparison but you can check out some pictures here: FP2 - Pictures Gallery
As per this test on Tweakers.net (Dutch), price/performance mid-range phones of ~280 EUR less (~250 EUR give or take) compete easily with FP2 every year, and they get better while FP2 doesn’t (except for camera). Its increasingly more common that devices in this range both 2.4 and 5 GHz WiFi, NFC, 4 GB RAM, Quick Charge, 1080p screen, decent battery life, good speaker, and decent camera. Not each model has each of these advantages, but the Motorola G5S Plus is a suffice choice if you want a cheap, decent, durable phone which lasts a while without a premium price. Though it is a moloch and will get official software updates for 2 years, another competitive option is Xiaomi Mi A1 though the camera lacks compared to the G5S Plus. But it is less bulky.
Of course you don’t get some freedoms you do get with a FP2 like modular hardware and by default unlocked bootloader (voids your warranty with Motorola when you unlock it) but 5 years lifetime of FP2 means end of 2020 as the phone is from end of 2015. Although with LOS (with or without GApps or MicroG) you can expect to be able run up2date software on it the same’s true for postmarket mid-range phones if you unlock the bootloader (possible with Xiaomi and Motorola and generally possible but do verify). Except maybe the firmware of specific chips. And these phones aren’t fair for the environment or workers either. That’s a thing you pay for when you buy a Fairphone as well.
That said, you could buy a what we call in Dutch tussendoortje (in-betweenie?); a decent phone for a couple of years until the FP3 comes out. The ones reviewed in the link I mentioned are mid-range around the 250 EUR range. You can go cheaper or more expensive, but it’d require a recent, other review and of course you will get what you pay for (following the review’s advice). If you can afford an iPhone, Apple does very good for the environment according to that recent Greenpeace report but that’s just one thing.
If you consider iPhone, you should also have a look at comparisons between FPOS Android 6 (or 7.1.2 if you run LOS) and the latest version of iOS which is I think 11.2.x these days.
Also, a valid advantage of an iOS device (especially high-end ones) is its resale value. But you did pay for that.