In 1950s, Ray Kroc the McDonald’s founder wanted to improve his French fries, he “stole” the secret from a Cafe restaurant owner by visiting his restaurant everyday ordering the same French fries, finally the Cafe boss was touched by his sincerity, revealed the secret to him …
Even in France, French families do not make such perfect French fries.
You may notice McDonald’s French fries are fried 2 times in different oil tanks : the first batch fried chips drain & cool aside, then fry again 2nd time just before serve.
Now you know the 2 “secret” temperatures (130 C & 180C).
I buy frozen (thin) French Fries package, use a Philips Airfryer, also airfry two times at these 2 different temperatures.
https://www.sbs.com.au/food/article/2020/05/06/how-make-perfect-potato-chip