All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
If your father has reached the stage of senility and is not in full possession of his mental faculties that are necessary for performing prayers properly, he is not obliged to perform prayer. However, you should fulfill your father’s wish to go to the mosque and remind him of the prayer times and accept his moods and behavior without any reproach to him.
Indeed, going to the mosque has a great deal of benefits for your father; he may follow the Imaam in the congregational prayer and see the worshipers. On the other hand, you can make up for the Sunnah prayers that you miss when you return home, which is, in fact, better.
Please note that being unable to witness Takbeerat Al-Ihraam i.e. opening Takbirah, or failing to pray in the first row in order to accompany your own father, would guarantee you more rewards than what you may gain if you witness Takbeerat Al-Ihraam i.e. opening Takbeerah, or prayed in the first row.
Allaah Knows best.