On the contrary, his virgin birth meant he could sit on David’s throne.
If Joseph had fathered him, he would have been disqualified from occupying the throne of David due to the curse on Jeconiah and his descendants according to the flesh (Jer 22:24-30; cf. Matt 1:6-7, 11, 16). However, the Messiah must be David’s son (2 Sam 7; Ps 89; Isa 11), so this creates a redemptive-historical dilemma: If he is fathered by Joseph, he is disqualified. If he is not descended from David at all, he is disqualified.
The virgin birth resolves this dilemma. Jesus is legally Davidic (via Joseph, his legal father), granting him lawful claim to the throne and fulfilling the Davidic promise, and also biologically Davidic (via Mary), but through Nathan, not Solomon, thereby avoiding the Jeconiah curse.