It all started with a note at my local cafe. Working on Keychain since 2022 had already piqued my interest in how we pay for things, but this simple sign opened my eyes to a startling reality:3% processing fees + Hardware costsThis sign made me think hard about how money moves in our world. Every time I swiped my card, tapped my phone, or clicked "pay now," I realized I was part of a story of silent costs and hidden players. I thought about cash. It's simple. A $50 bill stays $50 no matt...