Reuben was supposed to inherit everything. As the firstborn of Jacob, three crowns rested on his head by right — bechorah (the birthright), kehunah (the priesthood), and malchut (the kingdom). Targum Pseudo-Jonathan spells out what Jacob's deathbed words in Genesis 49:3 only compress. "To thee belonged the birthright, and the high priesthood, and the kingdom."
Past tense. Belonged. A single act at Bilhah's tent cost Reuben all three.
Jacob names the redistribution without flinching. "The birthright is given to Joseph, and the kingdom to Jehuda, and the priesthood to Levi." Each crown finds a new head. Joseph gets the double portion through Ephraim and Menasheh. Judah becomes the royal line from which David and the Messiah will emerge. Levi inherits the altar.
The Targum preserves a hard truth the Hebrew Bible does not flinch from: a single impulsive sin can rearrange a thousand years of destiny. But notice what Jacob does not do. He does not disown Reuben. Reuben remains a tribe, remains counted, remains blessed in his own way in the verses to come. The crowns are gone. The son is not.