I was (still am, though not active) interested in embedded programming. Though for complete newbie entering into arm gnu embedded programming toolchain was very steep learning curve and I was not willing to put huge amount of cash into some proprietary IDE.
So my hobby was limited to atmel's micro-controllers, which were more than I needed for my interest, though it was always interesting to try ARM micro-controllers.
Maybe I need to resurrect plans for programming ARM. Though probably bare metal programming is getting less and less attention, due to great and user-friendly platforms like arduino, raspberry pi (and all ecosystem of super powerful credit card computers), micropython, etc. But it's always a great pleasure to run a bare metal system with greatest performance and power efficiency.