After making exact same configuration as on different pc - same paths, same files, same installation and still being unable to load silent mod I followed the XextFindDisplay I encountered some very old topics about nvidia proprietary driver having issues with linking so preloading libraries was a workaround which in the end fixed my issue.
LD_PRELOAD=/usr/lib32/libXext.so.6 etl
After starting et like that and loading silent mod all libraries were loaded properly:
----- finished R_Init -----
Sys_LoadGameDll -> FS_CL_ExtractFromPakFile(/home/shana/.etlegacy, silent, ui.mp.i386.so)
Sys_LoadDll(/home/shana/.etlegacy/silent/ui.mp.i386.so)... succeeded
Sys_LoadDll(silent/ui) found vmMain function at 0xe9670210
This topic can be marked as solved. Thank you for the help
Shana's post in Clean etLegacy 2.76 silent 0.9.0 error reading libraries(XextFindDisplay) was marked as the answer