You can't prove that by me, see there's a contingent of old timers here who collect the less than perfect knives from yesteryear. We see a large variation of condition from broken blades to weak/broken springs and missing handles. I constantly see boxes of 70+ year old knives at yard sales and flea markets. Someone's hanging into them for a reason.
One common reason that you find broken old knives is the same reason you find broken new knives, abuse and neglect. People have abused knives for as long as they've been around, now a day's if we shall the top of a knife we send it back for repair, heck they even have spa treatments for knives these days so of course they seem like they're made better.
I think if you looked at today's knives a hundred years from now you'd find the same knives were either put away in perfect museum quality condition, broken in somebody's cigar box or sock drawer or slightly worn but functional nonetheless and being carried by someone like me in their pocket.
I think more companies made knives better and with more pride back then and without getting into the offshore issue there are only a handful of US manufacturers compared to 100 years ago when the competition was fierce. Nowadays if a knife is stamped USA anywhere on it our country pride kicks in and we'll buy it because we all know we make only the best.
No I don't think that's knives are better,I think they're better more consistently because of quality control programs but back in the day there was another type of quality control that required no program or supervision. It was called pride in your work, craftsmanship meant something to everyone. Those words are beginning to be heard more frequently these days, the remaining US manufacturers are all competing for our dollars and they're dealing with a more educated consumer these days. Modern technology affords us instant appraisals of current knives and their dependability. Between YouTube and online forums the US makers had to step up their game.
Let's compare today's knives a hundred years from now, I'll bet you'll find there will be more mint prefect condition knives than broken abused knives from the same time frame and you'll find the new 200+ year old knives in the same condition and the garage sales and flea markets will still be selling broken knives from the 20s-70s to people like me and someone will ask the same question again, "are today's knives made any better than the knives of yesteryear?" Of course no, we just take better care of them... I don't care how good a knife is but any knife neglected and abused is due to fail, it's inevitable.
I wish I had the ability to succinctly get my thoughts across like Jack, unfortunately I'm too dang wordy and what Jack can say in two or three sentences takes me a novel to say...