There is not enough evidence that they are there. Sainthood is not given by God. It’s given by the church.
A “saint” may be sleeping until the time of the Second Coming.
Christ Himself said that God is the God of the living, not of the dead, and all live to Him. Abraham, Isaac, Jacob - and Moses and Elijah, who were seen conversing with Christ on Mt. Horeb.
The Church does not and has never claimed to "give" sainthood. She simply recognizes those whose life and works show forth uncontradicted evidence of sainthood -- as mentors and good examples for the faithful.