You ask interesting questions for I hope a good discussion.
My first thought is we shouldn't expect machines to last "forever". The more "bells and whistles", the more there is to go wrong. Could we still be driving the first car we owned on a regular basis? (I think MrOK might like his 67 Barracuda back, but not sure how it would have survived almost 50 years and four kids, three of which are boys!) True there are many dependable mechanical machines out there. Singer's Featherweight comes to mind, but it only sews a straight stitch. I have had a Bernina Virtuoso QE (a computerized machine) which I bought used close to 15 years ago. I haven't had problems with it. About 8 years ago I bought a basic Janome for my Grands to sew on. Well I really like how this little mechanical machine stitches and find I sew on it quite frequently. It has only 3 preset stitch lengths and widths and that is a big drawback to depend on it completely. When in comes time to replace the Bernina..say if the motherboard goes out, I will replace with another mechanical machine. I'm not sure where I would buy it. I like the security of buying a name brand machine from a dealer. I also have a serger which I never use and a used LongArm which I love as I would never get quilts finished without it!
Even though I have several decorative stitches on the Bernina, I seldom use them. I would rather piece quilts than use those decorative stitches. I challenge myself by making minature quilts. A person's machine preference depends on what they want to sew.
As for the future of quilting/sewing, there are fragments of the population that still sew clothes (I quit doing that long ago) and the internet has helped bring that community together just as it has for the quilting segment. There are people who appreciate handmade items; again the internet has helped those who don't craft find handmade items to purchase.
We are getting used to the "modern" and improvisational aspects of our craft; so what is next?