Hmmm, I don't think that nor did I mean to intimate that. What I do think is that lighter, more mobile equipment makes it easier to explore a scene, and thereby makes it more likely you'll find something of interest. It's more of a scouting mindset that a question of how serious the equipment makes you. I, myself have done plenty of work I like in every format available to me from 35mm to 5x4.
In any case, as I mentioned, I don't do this consciously. It just sort of happens sometimes when I am out and about with a lighter camera.
When I was younger, I thought equipment/format mattered greatly - if only I had better equipment, my images would be better. This turned out to be profoundly false. Later on, I thought it made no difference at all. I was an artist, by golly, and artists paint well with any brush. Now I realize that it does matter in several ways. First of all, the equipment/format strongly influences your style of shooting. 35mm encourages a more dynamic, in the moment style of work. 5x4 almost demands a much more contemplative way of working.
Some formats are also better suited for some subjects. No matter how hard I try, I cannot produce a good 35mm negative that captures a grand vista with a lot detail in it. This is the natural remit of 5x4.
Similarly, the ability to changes plane of focus on a field camera makes it a natural for things like tabletop work that 35mm and MF simply cannot touch.
Of late, I have become enamored of a hybrid approach made possible by my Graflex Speed Graphic. I get the dynamism of a relatively portable camera, with the rendering detail of 5x4.
Examples of recent work that I really like from various formats:
35mm:
6x9:
4x5: