Another thing I’d add is that, although there’s probably few things the Beatles did that you can’t find someone who’s done it before them, they were taking more risks with their ongoing success by using Indian instruments, psychedelic effects, relying on video clips to promote a single etc than a small time artist who wasn’t making hits. There was always the real risk that The Beatles would move away from their audience and lose commercial power. Their continued success seems inevitable to us now but it wasn’t back then. Any album or single could have been a bubble burster. There weren’t many artists who were commercial successes in 1964 who were still so at the end of the decade.
So even if they weren’t the absolute first to do something, the fact they were willing to take risks by to continually moving forward and trying different things means they deserve credit as innovators. It’s easier to innovate when you’ve got nothing to lose than when you’re on top of the world and conventional wisdom is to keep doing what you’re doing to maintain success.