So I have been through this dilemma several times. Obviously, it is hard to give a definitive answer. I have certainly had my share of cameras. Have I ever found that perfect camera that was the only one I ever needed? Yes, several times. For me, there is a balance between the ease of using a system and the quality. I never really enjoyed large-format film photography, even though I really liked the quality. I found the balance with medium-format film--I love the choices of format and camera types.
Then came digital. In a sense, that was really portable when you just think of the size and weight of the film you don't have to carry. I also always liked a paired down kit, preferring one or two lenses over a whole bag of optics. When I moved to digital, I went with a Pentax 645D system and it was amazing (still is). I had no problem hiking a day with the gear and photographing--there is a difference between simply carrying your gear and having no energy to actually take photographs and carrying your gear AND taking photographs. This has always been a factor in selecting my equipment is that I need to use it. I would rather just take a camera and a lens if that means taking a lot of images and perhaps missing out on a few opportunities because of a single focal length than taking a "perfect" set of lenses and cameras and being too fatigued to use them.
Then somewhere down the line, I got old. I still use my Pentax--that is a great system, but it does not really fit where I am. So I started thinking about what inspired me in my photography. I love rangefinder/viewfinder cameras. I love the spontaneity of shooting, being able to see and react to the world I am experiencing. I love the technique and skill that comes with making photographs. What is less important for me is making huge images. I like most of my photographs in the 20" to 30" range. I find that size intimate but also impactful (I have made my share of 60"+ prints, so it is not like I have not printed large (not of my work, but the largest print I have made was 168"X168"). So I looked for a system that would give a satisfying photographic experience and give me the print quality I would be satisfied with. Surprisingly, even for me, I settle on the Fujifilm X series cameras--I was thinking I would go to 35mm. I tested my 24MP X Pro2 on a 40" print, thinking if that was good, anything smaller would be better.
I have been very happy with my choice. Is it perfect? No. But that is kind of the point. Chasing "perfection" can be a bit of a trap--every year manufacturers release a new version of perfection. Are my images satisfying, yes. I think we easily fall into maximizing our equipment, when we should be optimizing it to defined criteria. (Take that, Dante!)
But I still have my Pentax if I want to scratch that itch...