So I’ve gone back and forth between Apple and Android for the past decade and a half: I currently daily an iPhone 12 mini because I like the UI, size, ease of use, and the fact that I don’t use my phone as a multimedia device. If I could do akin to GrapheneOS or CalyxOS on iPhone I’d stick to it.

In the future once my iPhone breaks or finally becomes obsolete, I intend to go to either a used Pixel or a Fairphone. Both are supported by secure OSs but I also dislike how big both of them are.

TLDR: love iPhones, appreciate Fairphones.

Samsung Ultra all the way. It has top of the world hardware, software support

AND I can customize my phone the way I want.

Well Nokia is a no no They don't allow bootloader unlock, I would recommend that you check which privacy oriented custom ROM you want to install and check the supported phones they have listed and buy one of those models for installing the ROM

HTC (Wildfire, Desire Z, [rip!]), Samsung (they are/were easy to flash; S3, S5, S7, A5 2017).
I once had Nexus 5 (by LG [rip!]) - I was disappointed, poor quality.

Nowadays, you should have control of a baseband firmware too!
So, looks like the Pixels are the best option.

The hardware is wholly unremarkable, but the pixel line supports Graphene. Custom Roms are a necessity if you care about privacy even a little bit, but there are other options.

Unfortunately in many places, illegal searches are the rule, not the exception and as such security is almost as critical. If you need security AND privacy there is simply no substitute.

Motorola hardware looks kinda nice though...