My dad still cooks better than me and he's 71

My Mum, at 86 and with incipient dementia, still made better pastry than I ever have.
Generally I think my cooking's tastier, but in her day they made a limited amount of things & light, buttery pastry was something that was strived for & talked about - no ready-roll back then.

To be honest, I would say that at 71, I wouldn't really expect your dad to have lost his touch yet, assuming that he is still in good health.
71 really isn't old these days.

My mum was always a great baker, as was her mum, and she was well into her 80s before there was any noticable decline in the standard of her cakes.
Mind you, I wish I could say the same about myself. At 65, I'm blaming my newest oven and / or changes in the ingredients available for the unpredictability of my own baking efforts over the last couple of years, but do sometimes worry that I might be the problem !!!

My dad baked the lightest cakes and most delicious scones.
He could cook anything better than most, sweet or savoury.

I, however, made better bread - probably because he wasn't
interested!

Oh this made me smile joining the RAF and still cooking. Some things just don't leave you do they.
And I completely get you on the meat and potato pie. My dad is the same, there are certain things that are just his, full stop. No competition.
And you're right that the real ones never lose it. It just becomes part of who they are.

I don’t think professional chefs ever lose their touch. My DS trained as a chef for three years and then joined the RAF to do something entirely different. He’s never lost his skills or his love for food and does most of the cooking at home. He’s far more imaginative than I am, but he can’t outdo me on his favourite - a good old fashion meat and potato pie!