At a ridiculous-scale, yes, but even models with 100k tris are doable on old machines. I find 30-40k to be overkill on most rock, tree, etc things. If you are using instances or even better, assemblies, then you can leverage nanite for that lack of instancing-overhead (read the paper a few links above) which does much to claw-back overhead.
Anything 4k should be set to streaming/virtual-textures (duh). For my part, extensive testing only confirms that w/nanite, VTs are net-gain overall.
Do we even need a 4k texture? I like to try and reuse 1k/2k textures as I can tile them and mix them up, hence ‘increasing’ resolution (texels vs pixels). Obviously a net-gain with smaller textures being moved around.