In the realm of live performance, I’m totally willing to give the Beatles a pass. They were by all reports a very good bar band by the time they left Hamburg. By the time they were trying to be much beyond a bar band, the tech wasn’t adequate to deal with the crowds. I can vouch that any loud show without stage monitors is a crapshoot; could be great, could be bad. Sage monitors were still a few years away when the Beatles tried their big shows, and in-ear monitors were sci-fi. If the tech would have been there, they could have even done a decent facsimile of their late album work. Why not, they’d played it before? They would have needed the incentive to work with each other enough, though. By the time they were really experimenting, they were fracturing enough that long practices were probably out of the question.
In the realm of studio trickery, the Beatles may have popularized the techniques for that generation, but I’m having a hard time thinking of techniques they used that weren’t already done by a predecessor. Les Paul has a better claim to 90% of it himself, and he was pretty popular. You can claim that it was the first time that such techniques were first coupled with good songwriting by the Beatles, but it seems to me that they didn’t do a lot that isn’t covered by Waiting for the Sunrise and Lover. They have multi-tracking by the same artist (in fact, it’s some of the earliest multi-tracking), speed alteration, and quite good songwriting/arranging. When the Beatles were extending the studio tricks of others, it was sometimes just because they new Martin could “fix it”. The one exception of this I can think of is “Tomorrow Never Knows”, I can’t think of a song structured around tape loops that preceded it. So, props to the Beatles there.
Now, as to whether they were a “boy band”? Oh yes, they were. Live up to it, love it. You love an early boy band and their vapid songs, and so do I. Get it out there. Work that tension out of those shoulders and your neck. Boy Band doesn’t mean that it’s not well done, and it doesn’t mean that the members are forever limited to that. That they developed beyond that has already been detailed in the thread. Their boy band status and success was what allowed them to popularize their experiments. If they hadn’t had success with obvious boy band pablum such as “She Loves You”, et al, they wouldn’t have been popularizing anything when they went experimental. They’d have had as tough a row to hoe, and have been as obscure as another great band that followed them on the Hamburg scene, The Monks. The Monks started without the “boy band” foundation, so they had a hard time getting heard, but they had to pull off their live performances as a result. In a world of an amazing live band vs. a band with million selling hits, guess which one is going to be easier to make popular?
So, yes, a band that was plentiful amounts of good, able to pivot when they needed to, and were lucky to pivot the right way and capitalize on their previous successes. So, very popular. Best of the best? Nah, it would be too easy of an answer, even if it were possible to prove it true. I’d even argue that holding the idea that they could be provably the best would result in stagnation in current musicians, anyway. There’s been plenty done since their demise that they couldn’t have anticipated, and their output after the band’s passing is mixed, at best.
If I can lay a semi-novel complaint against believing the Beatles were the best ever, it’s similar to rooting for General Motors. Sure they popularized things, they were the biggest band on the planet before they started experimenting beyond blending rock sensibilities with traditional pop, which isn’t especially groundbreaking, but they were the cute guys who were successful at it for the period. But to attempt to freeze things at that period before 1970, and say “yep, best” because of a lot of entirely debatable points makes you look like the people who claimed that Buddy Holly was still living forever somehow, or that Elvis is still the King.
On preview: YAY! Wall o’ text. No TL; DR this time. And, John Mace: when I was in high school decades ago, I heard a girl utter those words completely without irony.