VRAM
VRAM usage isn't a big problem, the game is well optimized for the right allocations at the respective resolutions. At low settings, sub-4K, without upscaling, you'll be perfectly fine with 8 GB or less. Even at max settings, 8 GB will be sufficient for 1080p and 1440p. Once you max out the texture pool setting, and enable frame generation you can hit around 15 GB.
While I've had some issues getting 8 GB cards, like the RTX 5060 Ti 8 GB, to run well in Indiana Jones, this is a non-issue in DOOM. Unlike Indiana Jones, the game will not crash when out of VRAM. I tested and confirmed that it is able to use system main memory as overflow when out of graphics VRAM. Of course the game will now run slower, but it won't crash anymore. You can see this in our 8 GB vs 16 GB results at 4K, which clearly show that cards with 8 GB are handicapped, but they continue running, which gives you a chance to adjust the settings. At max settings, at 1080p, which is the right resolution for RTX 5060 Ti, both 16 GB and 8 GB achieve the same performance, the same is true for 1440p with DLSS Quality.