Using RIOT you'll get at least multi-threading, power management, a choice of network stacks, a bunch of community-supported libraries and drivers with an extensive test suite, ...
Also, you'd have a clear upgrade path, as applications written for RIOT's API will compile (almost) unchanged for all of RIOT's target hardware. Arduino becomes to slow? Change some pin defines, re-compile for a fast Cortex-M. Intrigued by RISC-V's openness? Recompile for the Hivife1 to find out it's real-world performance with your application.
Using RIOT you'll get at least multi-threading, power management, a choice of network stacks, a bunch of community-supported libraries and drivers with an extensive test suite, ...
Also, you'd have a clear upgrade path, as applications written for RIOT's API will compile (almost) unchanged for all of RIOT's target hardware. Arduino becomes to slow? Change some pin defines, re-compile for a fast Cortex-M. Intrigued by RISC-V's openness? Recompile for the Hivife1 to find out it's real-world performance with your application.