With virtualization, probably forever? If the program still runs, and was compiled for x86 instruction sets, then essentially x86 is still "enduring" no matter the underlying hardware processing the instructions. The architecture of the physical device running the software will no doubt change, but software is hard to kill when it becomes so pervasive. Someone in the year 2324 is still going to want to run some game made in 2024, just because.
Does it really matter? Thanks to shared library dependency hell, I can't even reliably copy binary executables from one system to another, so until that is fixed I couldn't care less what architecture is running.
