It was a confluence of events but the main thing was playing clubs in Germany, basically playing covers for something like 50+ hours a week on and off for two years. And they were playing late at night to drunken crowds, so they could experiment and goof off too. That's how John, Paul, and George developed their impeccable harmonies, tight playing, and a massive repertoire of hits.
That's just an absolutely crazy amount of hours to be performing in such a short period of time, and nearly impossible for most musicians to actually get paid for (outside of relentless busking).
I think very few bands since have worked as hard as the Beatles. Their 2 years in Hamburg playing long hours in night clubs daily is something few bands can do (or would want to), and that forged them into something special (not just in technical musicmanship). The Beatles never shied from putting in the work.
It wasn't 2 full years, but... certainly, multiple stints of 8 hour sets for weeks on end - it's basically a full time job.
Other 'factors of the time'. They wanted to play rock and roll. There just wasn't THAT MUCH of it. In 1961... there were a few years of the genre, several albums by their heroes, but... it's not enough to play and attract people in bars for weeks on end. There were other factors too, but that constraint was one, that helped push them to expand a bit beyond just 'rock' stuff (some earlier standards, etc) to help differentiate themselves from other bands (and eventually self-composing as well).
By coming back from... IIRC, their second or third Hamburg stint, they had somewhere around 800 hours of playing together as a band. That just wasn't a thing (yet). I mean - not even most of their heroes/idols didn't have that much stage time as a single unit. The "self-contained rock band" really wasn't a "thing" yet.
I've been in bands, and we were never even in a position where we'd be able to play 6-7 hrs a night for weeks on end. I'm sure no one would have wanted to anyway (like you say).
Depends on what you mean by "like the Beatles." If you mean popularity, it's because there's only so much room culturally for artists to reach that level of popularity. They are essentially the mascot for Rock and Roll music and there's no changing that.
> So why aren’t there a bunch of bands like the Beatles?
"Like the Beatles" how?
They were at the right place at the right time (that is, the time where pop music was starting, hence you had less granularity), and singing in the "correct" language to get a massive audience.
Further than that, they were lucky to not get broken up or faded out early.
This in no way diminishes their work, but it was a hole in one.
In a way it's kinda of a Fermi paradox of bands, except there's no paradox because nowadays there are multiple bands (at smaller niches) with several very competent musicians playing. Or "manufacturing" bands.
Is Max Martin a lesser musician than Paul or John? Probably not really and I don't like most of his songs.
