Elsewhere the Bible says the earth will remain forever, for example Psalms 104:5.
So, does the Bible contradict itself? No, the problem is that people do not understand the Bible, and as Peter foretold unlearned and unsteady individuals twist the Scriptures, to their own destruction.
In the instance of Isaiah, Jehovah was contrasting the fragile temporary nature of all creation, particularly of the human civilization, with the surety and permanence of God’s salvation. The prophecy of Isaiah contains judgment messages that initially applied to Israel and the mighty empires of Assyria and Babylon. God foretold that he would overthrow those seemingly permanent institutions, which he did, which other prophecies likened to the heavens crashing and the toppling of mountains.
In the case of Israel, though, God stated that he was creating a new heavens and a new earth. That promise was fulfilled in miniature when Jerusalem was re-inhabited and given a new governor and priest. But obviously God did not create a new universe and new planet. Those are simply expressions to denote the grandness of God’s work.
When Christ said heaven and earth would pass away before his word failed to come true, that was not a statement declaring the earth was going to be destroyed. It was meant to emphasize the sureness of his word that the present system would be destroyed; that, if it were possible, the heavens and earth would fail before one letter of his word did. In truth, neither the heavens nor earth, nor the words of Jesus will ever fail, including his promise that the meek will inherit the earth.