Thicker with more ports is not a “variant”. That’s an entirely custom housing with a different battery and possibly a different board to support the new ports. This is equivalent to the split between MacBook and MacBook Pro.

Dell, HP, and Lenovo also do not do what Apple is asked to do here. You can buy a thick heavy laptop from Dell. You cannot, however, buy a slightly thicker, slightly heavier XPS 13. If you want the flagship “ultra book”, you buy the one they sell. Otherwise you buy the plastic Inspiron or whatever which is an entirely different class of product and does not feel particularly premium.