I get this shimmering too. Its most visible in simulator games, which is all I really play. DCS, X Plane and Elite Dangerous all show shimmering. Enabling SMAA in ED helps, but the other games dont support it. I think TAA would help in DCS as it uses deferred rendering but there’s no option, not sure about X Plane. AFS2 is nice with Advanced Anti Alias enabled in the options but as people have said, its very basic from a sim point of view but it does look nice and run very well.
I think the 5k+ suffers from aliasing and shimmering most, but provides the best clarity in cockpits compared to the 8k which seems to naturally anti-alias by the fact the pixel grid is not orthogonal. Hopefully there will be a solution to this soon, some settings in Nvidia control panel help a bit though such as “Texture filtering = High Quality” among others.