I heard of GD32F103 at FOSDEM this February.
I was informed about this article: https://smdprutser.nl/blog/stm32f103-vs-gd32f103/
For me, it was difficult to get the chip (I am in Japan). So, I asked my friend in China, and finally got the chip.
Then, I modified my firmware to support the chip (the firmware is originally written for STM32F103).
Now, I ordered my own PCBA to Fusion PCBA using GD32F103TBU6. I believe more people want to use GD32F103.
It’s fast and cheap.