Everything you say is true @stuartk, except for your final sentence.
I only recently learned of Levon, Rick, and Richard’s use of hard narcotics. Clapton recently talked about the breakup of The Band, and mentioned how those three members had gotten clean by the time of The Band’s reunion. He thought they then sounded better than they ever had (I prefer Jim Weider’s Telecaster playing to Robertson’s Stratocaster playing), and that Robbie may have regretted his decision to dissolve the group. Levon never wanted to, and I guess went along with it partly out of his drug influenced state of mind. Their reunion was severely hampered by the suicide of pianist/singer Richard Manuel, imo the heart and soul of The Band. What a great, great singer, and an unusually interesting drummer (he plays drums on half the songs on the brown album).
Regarding your last sentence, there are a couple of matters involved. Levon’s change in attitude began when the royalty checks for the brown album started rolling in: Robbie’s were a lot bigger than everyone else’s, a natural result of his taking credit for most of the songwriting on the album.
Levon’s view was that the writing of the songs was just a skeleton, the fully realized song reaching fruition only with the contributions of the other four members. Since Robbie’s contribution after the songwriting was only the guitar playing (don’t be fooled by Robbie’s "singing" in The Last Waltz. The Band’s harmonies were two and three part, not four. If you listen when Levon, Rick, and Richard are singing together, do you hear Robbie’s voice? No, you don’t. He’s faking it. All those shots of him "singing" in the movie should have been coverage of Richard, who is grossly ignored by Scorsese), the others doing all the singing and the vast majority of the playing of instruments, that is a justifiable view on the matter of equitability, and compensation for contributions leading to the final product..Levon was the leader of The Band musically, playing an indispensable role in crafting the arrangements, sound, and feel of The Band’s songs.
Robbie’s view was that what the other members of The Band did was merely what musicians do, and should not be considered part of songwriting. That too is a justifiable view of the matter, though one more old school (Tin Pan Alley tradition, rather than Rock ’n’ Roll reality) than perhaps appropriate for the situation.
And then there is the matter of The Last Waltz. It was all Robbie’s idea, and his relationship with the money men resulted in his being credited with being an associate producer of the movie. That meant he got a big paycheck off the top of the proceeds generated from the movie (gross profit), while the other members of The Band received only compensation from the net profit the movie made, if any. There wasn’t any. That REALLY pissed off Levon.
Then there is the matter of John Simon, the producer of the first and second Band albums. Robbie approached him with an offer to do all the arrangements for The Last Waltz, writing charts for the horns, etc. Simon told him he hadn’t received any royalty checks from Capital Records in a LONG time, and wasn’t going to do the film until he had. Robertson came back with a royalty check and an offer: sign away all future royalties for the two Band albums he produced in exchange for a percentage of the net profit the film made. Simon agreed to it, and has never again received a royalty check from Capitol Records. He also made no money for his work on The Last Waltz, as the cost of making the film, promoting it, etc., resulted in there being no net profit. But here’s the kicker: Robertson knew that would likely be the case, and was why he made sure he himself got his cut off the top of the film’s gross profit. Disgraceful behavior, one musician knowingly using another for his own personal gain at the cost of the other’s.