The Beatles mean as much to kids today as they did to those even a generation ago I'm an elder millennial. As a teen in the late 1990s, I loved The Beatles. Practically all my peers did as well. I suppose I grew up with them because as a child in the 1980s AM and FM radio would play hits from Buddy Holly and Elvis onward. But even among all the other music we were exposed to from the 50s on, the Beatles stood out - not necessarily the best, but certainly interesting and special.
With P2P and iTunes and streaming emerging in the aughts, they dropped off almost immediately from those lofty heights. Of their contemporaries, the harmonies and brand of kitsch provided by The Beach Boys are more popular. Certainly The Kinks are much cooler. Pink Floyd more experimental. The Rolling Stones and The Who rocked harder.
Then we move on to the bands who came of age in the 70s and they are less twee, more weary, more glam. Less of McCartney's music hall influence, that's for sure.
I think the reason the Beatles meant a lot to me in the 90s is that they were available. And still marketable. So cute and witty. Wild in a controlled way. Rebellious in an acceptable way.
The music stands up. The singing is beautiful, musicianship peerless, writing startling. They are still hugely influential. But I would say Elvis means more to people younger than me than The Beatles do. I think his sexual heat, and their relative lackthereof, may be a reason.
I'm just spitballing here. But I am surprised their popularity waned to this extent.