Consolidation of brand ownership, as you point out, result in cost cutting in materials and manufacturing.
Samsonite, for example, owns the Tumi, American Tourister, Gregory, High Sierra, Kamiliant, ebags, Lipault and Hartmann brand names.
Badge engineering, i.e. slapping a name on a generic bag is not uncommon either and teh bags may sell at different price points.
Which is why it is important to know what to look for in zippers, material etc. if you are buying a premium brands.
How true, for many things beyond luggage.
All depends on needs and budget.
In my case, my carryon and computer bag are all high quality from small manufacturers; since they get used a lot.
Since I rarely check a bag, on sale, preferably in a butt ugly color so no one thinks it's their's, is my go to. Limited use means they last 10+ years before they are done.