A few thoughts.
The Beatles began performing live as "The Beatles" on 15 August 1960 at the Jacaranda in Liverpool and ceased to be a performing group at Candlestick Park, San Francisco, August 29, 1966. After that they had a little over three years as a recording act up until January 1970. Paul McCartney is listed as the richest of all "Rock" stars, with just over a billion dollars and continues performing to this day at the advanced age of 83. For many, The Beatles represent the peak of musical accomplishment among all "Rock" groups.
The biggest single collection of performances by the group are their radio performances for the BBC from March 1962 to June 1965. I've seen bootleg boxes containing 10 CDs worth of recordings, Apple Inc has seen fit to issue 4 CDs of material including 4 interview tracks from 1965/1966. The BBC material has the group performing, mostly from 1962 to 1963, mostly unedited and decidedly monaural, in pretty bad sound. But these recordings are the best window into the performance skills of the group. Dare I say they are very rough sounding? They may have established templates for what eventually became "Rock", but they started with lots of covers of R & B and early Rock 'n' Roll with a few show tunes thrown in. And there really wasn't that much going on musically in their earliest songs. At least that's my unrequested opinion. As it became more difficult for them to perform in public—their "fans" wouldn't let them—they turned to the studio as an instrument, their songs became more complex, and they drifted further away from their initial style.
But so did everybody else, from the Kinks and the Who to the Zombies and the Beach Boys. That is to say, The Beatles were given credit for innovations that others were responsible, such as producer George Martin and engineer Geoff Emerick, not to mention Joe Meek and Glyn Johns. The existence of the group was 10 years, all told. In the aftermath, two members did all they could to ride on the coattails of the bands' success, one did all he could to establish himself as an artist before retreating from the public eye and one vacillated between exploding the myth, retreating from view and finally attempting a comeback only to meet a tragic end, further mythologizing his life.
When I looked up the "richest rock stars" Taylor Swift was nowhere to be found, though her total income is double that of Paul McCartney. Of course she doesn't produce "rock", but she is, right now, one of the biggest stars in popular music's firmament. Come to think of it, Paul McCartney's "Greatest Hit"—"Yesterday"—isn't anything like "Rock". Swift signed with Sony/ATV Tree Music Publishing in 2004. At the age of 14 she was the youngest signee in the publishing company's history. In terms of total music sales, she is exceeded only by Rihanna. You might not like her music, but a lot of people do. "Popular music is popular because a lot of people like it" as Irving Berlin once said, and he should know. As to the issue of her music enduring, there's a lot of music of marginal skill that has persisted. And many times, that sort of music becomes the template of music of the future. There's also a lot of music that isn't popular that turned out to be influential anyway. Charlie Parker will never become truly popular, neither will Charlie Poole, though both turned out to be highly influential. The phenomenon of Taylor Swift is such that she will be influential for a long time, if for no other reason than the desire of other musicians to have her kind of success.
