Mmmm, I certainly did get transfer onto my clove coloured leather in the RC and do have transfer onto the white bolsters of my RX, (guess also onto the black centres but it's not visible) but it's relatively easily removed using the giant 'Pritt Stick' stain remover included in the Lexus leather cleaning kit.
All modern car leathers are PU coated, sealed and impervious. So this is just a surface effect. Some high end models have semi aniline leather which is 'naked' and must be cleaned and treated differently (try the water drop test, apply a drop of water onto the leather, if it's absorbed, naked leather, if it just sits there, sealed leather). I had my C class Mercedes retrimmed with naked nappa leather. Sumptuously soft and smelled lovely but OMG was it a pain to maintain, never again....
Cracking in the surface on 'normal' car seats is just grit and muck eroding the PU coating in the creases. Good routine cleaning with a damp cloth is really all that's needed. Conditioners just sit on the surface and can actually exacerbate the problem by attracting dirt, as it cannot be absorbed by the leather.
Leather colourants and restorers work well by resealing the surface, filling the cracks. Seats must be scrupulously clean before applying.