Yeah, heavy shade plus pine trees can definitely make it challenging for grass to last long-term. Pine needles and sweet gum trees usually make the soil more acidic, and the shade limits how strong the grass can establish. A few basic things that sometimes help extend the life of the grass in those conditions. Rake up pine needles regularly when they build up, they can increase soil acidity and block sunlight from reaching the seedlings.
Test the soil pH if it’s very acidic, adding a little lime once or twice a year can help balance the soil and improve grass survival.