This is an interesting discussion to follow. I don't own a LF but am finding myself more and more tempted in that direction. My staple format is currently 6x7 in an RB67.
I don't know whether I'm "mature"
I am somewhere between "youthful" and "middle aged" in the mid-30s. But as time passes, I find that I get more gratification from hobbies which entail slowing down and doing things in a more deliberate fashion. Cooking food which takes a couple of days to prepare. Brewing beer which takes months to mature. And, of course, taking photographs in a way which forces me to slow down, think through what is on the ground glass, and then either patiently process (B&W) or wait for a lab (Colour).
Although I've always had a bit of a traditionalist streak, I don't think that I had the patience in my 20s. And in my 30s I'm finding pleasure in retreating from the acceleration and pressure of work in slower pursuits.
So now I'm trying to tempt a pro I know into selling me his no-longer-used 4x5