Definitely not always better.
Of course, a run-of-the-mill prefab house is worse than a nice used one.
But I can only speak for myself. We are currently building and I can decide every millimeter of the house. The shape, gables here, Danish narrow cladding..., Should the utility room be 12 or better 15 m2. Kitchen open or closed, etc. For me, that is the ultimate. Our house is 95% shaped by me according to my wishes. The architect talked me into 5% more.
And when I see that used houses cost about the same, I cannot understand how anyone can prefer not to build new.