Why? It's readily available in many places in China, including aliexpress. There is a chance code could be compatible with something else depending on what peripherals it uses as MCU is based on 8051 core. Very unlikely that there is a direct substitute though.
The actual mcu is burned out. I think of using some popular mcu to program it with recreated firmware.
I'm not sure that chinese mcu is compatible with my programmers, compilers.
It's certainly compatible with any 8051 compiler, it has JTAG so probably you don't need to buy a specific programmer/debugger.
seems enhanced 8051 family ... and i think STC does it too ??
It seems unlikely to me you'll find another microcontroller with the same pinout, I don't think this one is standard. But maybe there's one.
What I'd do, is use whatever MCU you want that is suitable (i.e. compatible voltage/clocking/IO features) and then either:
1. make a PCB module containing the new MCU, that fits the existing footprint, or
2. dead-bug/point to point wire the new MCU to the old footprint