In some ways you are correct, especially in the 2000s. For optics, modern lenses have many elements with good coatings, and are computer designed in ways that were not possible before because lack of computational power. Modern lenses can reproduce lens charts better than older ones for sure. And structurally, fatigue, etc., with FEA and other computational methods, designers can design components and systems so they do not fail as easily. On the other hand, how long do they design them to last? 10 years? 20 years? Next model? Cameras designed in the 20s-50s were designed to last forever (they did not succeed completely for sure). They were over designed. Many older cameras had very heavy bodies , frame and structure. They also had weak points, and this is where they fail.
Maybe. As long as you can keep the electronics going.
I just feel you have a better chance with an older, simpler, well built mechanical camera as long as repairs are available. My Konica Big Mini is a great travel camera. I just hope it does not end up bricking at some point.