I have the older FP3+ model (last one with a headphone jack) - if you’ve got the S22 it’s definitely going to be a downgrade sadly.
My previous device was over half a decade old, so I got a boost in performance and better cameras, however I do find myself using Gcam if I want a point-and-shoot experience (particularly in the dark with Night Sight), and OpenCamera otherwise. The cameras are ok, just the apps don’t make the most of them IMO.
The FP4 I believe improves on these quite a bit, especially in the performance department, but it hasn’t got a headphone jack. There FP forums are really active with people discussing the device - there’s a thread dedicated to photos taken with the device if you want a better feel of the camera’s capabilities in particular
As for my FP3 device in general, I really like it. It’s well supported by various custom ROMs, quite a few documented teardowns on the forum. I’ve replaced my vibration sensor, the last one burned out due to my love of haptic feedback 😅. I believe there’s also a PostmarketOS linux distro available for the device too. Taking it apart is really easy, all the screws are identical sizes and no special tools are needed.
I just wish Fairphone had additional resources to pour into the software side of things - the device supports partially charging the battery, and reducing the quick charge speed, but these are not options available the settings… You can only set these via the command line/Termux with a rooted device. Google has also been giving them a hassle over the fingerprint sensor and certification - as of Android 13 I believe the fingerprint sensor in my device no longer will work in most apps as it does now on Android 10