You can get STM32 boards for the same price (Blue Pill/Black Pill). ARM does have 'apt-get install arduino'-level of convenience. You can actually use the Ardui

You can get STM32 boards for the same price (Blue Pill/Black Pill). ARM does have 'apt-get install arduino'-level of convenience. You can actually use the Arduino IDE through stm32duino, which is literally a matter of adding an additional board manager URL to the IDE. Moreover, you program STM32 boards (besides mBed, etc.) with Rust, which is also easily set up. The Rust embedded ecosystem is much smaller, but still nice for hobbyists. Moreover Rust with ARM cross-compilation is easy to set up. Another nice feature is most ARM CPUs is that setting up and using gdb is trivial (e.g. with STM32s it's usually a matter of starting OpenOCD and then connecting to that with gdb).