I admit to owning and carrying one-hander knives and I also own/carry Victorinox SAKs. I do so because I like the feature of one-hand opening and just the knives themselves.
That said, years ago I lived in Taiwan for several years, and my only knife was a Victorinox Spartan; it was a version with the red plastic handle but without the toothpick/tweezers. I ended up using and carrying that knife for well over ten years. In fact, it had been used before I got it; my father had used it about 7 years before that. It held up several more years after returning Stateside, and with very little maintenance. I've now retired it, but it is still fully functional, though somewhat beat up and ugly-looking now.
Nowadays, I often carry a Vic Pioneer with red Alox handles, and either a red Classic or a black Executive, along with whatever else I carry. As much as I love my one-handers, probably the majority of my daily uses involve one of my SAKs. My dad grew up on a farm, and used to carry small carbon-steel Camillus knives made decades ago, using/sharpening them until the blades resembles dark-brown toothpicks. He sure got lots of hard use out of those. IMO, it's really the skill and experience of the user that can outdo super-steels and ultra-modern designs, though once again, I'll say I do like a lot of the modern knives, too.
Jim