So that's not actually the case.

The Hebrew name that we get Joshua from is יְהוֹשֻׁעַ Yehoshua. That gets rendered in English as Joshua, adopted straight from Biblical Hebrew.

Jesus's name on the other hand was Aramaic יֵשׁוּע Yeshu / Hebrew יֵשׁוּעַ Yeshua. The Gospels, written in Greek, render it as Ἰησοῦς Iesous (seemingly coming from the Aramaic, not Hebrew - it's quite likely Aramaic would have been the every day language of Jesus and his disciples). That was adopted into Latin as Iesus, which came into Middle English as Jhesus/Iesus and evolved into Modern English Jesus.

More can be (and already has been! Shout out to the people who've commented already) said, but I wrote quite a long answer explaining how we got from Yeshua to Jesus, but not for Joshua, here.