Of course they are! Prayers aren’t judged “invalid” or not “liturgical” just because you substitute modern pronouns for older ones. You’re thinking about prayer too legalistically. The Pharisees followed the Law to the letter, i.e., made sure they followed their “liturgy” precisely, and yet their prayers were not heard because their hearts were far from God.
Your prayers are “approved” by God when they come from a humble and contrite heart, a heart that acknowledges its sins and seeks mercy from God and desires to be an instrument of mercy to others. Your prayer is “liturgical” when you participate in the public prayers of the church; for example, the Mass and the Liturgy of the Hours. If you think that changing a few words no longer makes a prayer “liturgical,” then you need to change that view, for that is treating public prayer as if it was some kind of magical incantation where you must pronounce all the words correctly in order to receive the desired result. That is superstitious and contrary to the Christian understanding of prayer, which is based off faith.