have done the exact same rundown that the original poster has done to attempt to fix the issues on my newer computer
i have 2 computers, one is 8 years old (FX6300/gtx970/16gbRAM) doesn't have the issue
but my one and a half year old system (3600X/rtx3060/32gbRAM) is the one not able to run without crashing constantly,

some errors i've taken screenshots of are:
???+1EC8299ED0
???+1EC40FF3370
???+1EC42901318
???+10C4
???+1EC42900FC8

ffxiv_dx11.exe+14E973F
ffxiv_dx11.exe+14D06B4
ffxiv_dx11.exe+1236C73F
ffxiv_dx11.exe+117C47D
ffxiv_dx11.exe+114AA09
ffxiv_dx11.exe+114C21D
ffxiv_dx11.exe+1742A0
ffxiv_dx11.exe+172BBB

Had one crash with 2 error messages at the same time and they were
first error message:
nvwgf2umx.dll+3CBE22
nvwgf2umx.dll+716DC
nvwgf2umx.dll+BF557F
nvwgf2umx.dll+BF54FA
nvwgf2umx.dll+BEA1FD
nvwgf2umx.dll+582D7A
nvwgf2umx.dll+11F6914
KERNEL32.DLL+17034
second error window:
nvwgf2umx.dll+3D5AF1
d3d11.dll+12707E
d3d11.dll+126F10
d3d11.dll+12C398
ffxiv_dx11.exe+31544B
ffxiv_dx11.exe+30A5F4
ffxiv_dx11.exe+310156
ffxiv_dx11.exe+30D6B1