My arguments, and very much an opinion, not facts The undefeated and the way he dominates does it for me. Jones has three debatable losses Gus1, Santos and Reyes (not conuting Hamill). GSP lost twice (though avenged both) and should have lost to Hendricks. Silva in his prime was on par in dominance but his way overdue retirement and 8 fight streak of no wins (Brunson won) spoils it.
Jones would be my argument for being technically undefeated, dominating great fighters (Cormier twice, Gus2, Roid Vitor, Bader, Rua, Machida, Glover, Santos), damn that's a true murderers row I might change