Aircraft of earlier generations tended to have nearly rigid wings. Now they are designed to be more flexible. " To give a smoother ride..." so we were then told.
Someone published a video of the wingtips of an aircraft in "moderate turbulence" on this thread a year or two ago.
{ As a SLF I try to watch the wing-tips lift, on the opposite side to where I am sitting on the aircraft, as they start to do their job on T/O. This was something I had been unable to see as a pilot. And our wings, then, were supposed to be (very nearly) rigid, anyway!)
Perhaps the " smoother ride " story may have been at least partially true !