I am afraid there is nothing like minimalism when we talk about mobile phones. It is basically all or nothing. I mean, it seems like everybody only thinks about social media apps but I don't care about social media, I want my phone to run apps that control my smart home appliances, contain my public transport tickets, my ID card, my air tickets and other such convenient stuff. Most of these apps basically only exist for iOS or Android and some of them only work when downloaded from the official stores. So any phone achieving minimalism by using custom OS is just unusable for me and is equal to a dumb phone.