The Raspberry Pi is a single-board computer with native support for UART, SPI, I2C, CSI, and more. There's a large ecosystem of HATs, sensors, and peripherals built specifically for it. Most mini PCs rely on USB for peripherals, which isn't ideal for embedded use cases. Additionally, mini PCs tend to be discontinued within 2–3 years, whereas the Pi has much longer lifecycle over a decade. It's closer to an ARM development board, and those alternatives aren't cheap.

There are plenty of Pi clone boards at lower prices, but they have smaller communities and less documentation. When you hit an unexpected problem, it can be hard to find solutions or get support.