As the owner of a Fairphone 4, don't get one.
It's sold as a 5G phone but crashes intermittently if you actually enable 5G. I bought a 5G phone and I'm still on 4G. I wish I could say that's the most of the problems, I could live with that.
The software support, in my opinion, is falsely advertised. You do get 5 years of kernel and Android updates but the system-on-chip updates, which aren't made by Fairphone, end October of this year. That's a whole important part of the updates which cease only 2 years into support.
Then, there's the real kicker; the hardware root of trust has the (publicly available) AOSP test keys installed. This means anyone can sign and flash a verified ROM if they have access to the unlocked phone. That's perhaps not too important for most people, but it screams incompetence and it means you cannot trust a second hand device.
When the SoC support is up, I'm moving to a Pixel. I'm done rolling the dice on Android phone manufacturers and I want a well implemented device.