Old school mom

So can y’all help me understand where my mom is coming from. I’ve been dating my boyfriend for a year now. She told me that I should never let him drive my car. I’m like okay I understand that because I’m still living in y’all house and y’all pay for it. But for example my mom wants my boyfriend to come to church sometimes. He has a car but he has car trouble sometimes. So if he does she said I can’t pick him up at all to bring him to church with me. But besides church I can’t pick him up. So am I missing something I wanted her to explain why but she didn’t say anything. Maybe y’all can interpret. He drives his car almost all the time. I rarely drive at all when we are together.

We are in our early 20’s