GM! For a serious BTC stack a dedicated desktop computer is by far the best approach. Phones are fine for a modest stack, but not for retiring your family.
Don’t play games, browse the internet, and then handle your generational wealth on the same computer. You can get a used M1/M2 Mac Mini for $250-400. https://news.sky.com/story/meta-found-covertly-tracking-android-users-through-instagram-and-facebook-13379083