Your suggestion to ship glibc caused coffee to end up over my keyboard :) This is the road to hell, but you'd only know that if you had the slightest clue of the ABI interactions involved in swapping out a core library like that - starting with the reality that parts of the (probably binary-only) graphics stack must be linked and loaded in-process, and they naturally depend on at a minimum glibc. Your suggestion is to effectively ship the game in the form of its own Linux distro, which is of course complete nonsense.
Snap and Flatpack will hopefully help with the dependency aging problem, but they're brand new, and they both still suck one way or another.
To give you an idea of what swapping out glibc would involve, here is the list of shared libraries loaded by 'glxgears' on my machine, arguably the simplest possible OpenGL program:
/lib/x86_64-linux-gnu/ld-2.28.so
/lib/x86_64-linux-gnu/libbsd.so.0.9.1
/lib/x86_64-linux-gnu/libc-2.28.so
/lib/x86_64-linux-gnu/libdl-2.28.so
/lib/x86_64-linux-gnu/libexpat.so.1.6.8
/lib/x86_64-linux-gnu/libgcc_s.so.1
/lib/x86_64-linux-gnu/libm-2.28.so
/lib/x86_64-linux-gnu/libnsl-2.28.so
/lib/x86_64-linux-gnu/libnss_compat-2.28.so
/lib/x86_64-linux-gnu/libnss_files-2.28.so
/lib/x86_64-linux-gnu/libnss_nis-2.28.so
/lib/x86_64-linux-gnu/libpthread-2.28.so
/lib/x86_64-linux-gnu/librt-2.28.so
/lib/x86_64-linux-gnu/libz.so.1.2.11
/usr/lib/x86_64-linux-gnu/dri/i965_dri.so
/usr/lib/x86_64-linux-gnu/libdrm_intel.so.1.0.0
/usr/lib/x86_64-linux-gnu/libdrm_nouveau.so.2.0.0
/usr/lib/x86_64-linux-gnu/libdrm_radeon.so.1.0.1
/usr/lib/x86_64-linux-gnu/libdrm.so.2.4.0
/usr/lib/x86_64-linux-gnu/libglapi.so.0.0.0
/usr/lib/x86_64-linux-gnu/libGLdispatch.so.0.0.0
/usr/lib/x86_64-linux-gnu/libGL.so.1.7.0
/usr/lib/x86_64-linux-gnu/libGLX_mesa.so.0.0.0
/usr/lib/x86_64-linux-gnu/libGLX.so.0.0.0
/usr/lib/x86_64-linux-gnu/libpciaccess.so.0.11.1
/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.25
/usr/lib/x86_64-linux-gnu/libX11.so.6.3.0
/usr/lib/x86_64-linux-gnu/libX11-xcb.so.1.0.0
/usr/lib/x86_64-linux-gnu/libXau.so.6.0.0
/usr/lib/x86_64-linux-gnu/libxcb-dri2.so.0.0.0
/usr/lib/x86_64-linux-gnu/libxcb-dri3.so.0.0.0
/usr/lib/x86_64-linux-gnu/libxcb-glx.so.0.0.0
/usr/lib/x86_64-linux-gnu/libxcb-present.so.0.0.0
/usr/lib/x86_64-linux-gnu/libxcb.so.1.1.0
/usr/lib/x86_64-linux-gnu/libxcb-sync.so.1.0.0
/usr/lib/x86_64-linux-gnu/libXdamage.so.1.1.0
/usr/lib/x86_64-linux-gnu/libXdmcp.so.6.0.0
/usr/lib/x86_64-linux-gnu/libXext.so.6.4.0
/usr/lib/x86_64-linux-gnu/libXfixes.so.3.1.0
/usr/lib/x86_64-linux-gnu/libxshmfence.so.1.0.0
/usr/lib/x86_64-linux-gnu/libXxf86vm.so.1.0.0