It's such a stark contrast with Kobe, they both grew up partially overseas in relative privilege with a life of nothing but basketball and stardom, but Kobe, while not anyone's idea of a selfless and well-adjusted person IMO, channeled that into obsessive work and competitiveness. I suppose Ben has just never been challenged (competitively or by any teammates or coaches).
Sixers don't get off the hook for that part (coach knew him and his family too well, owners liked to party with the players). Brown coddled him, I'd say, because he knew this would be the result if he didn't, and Rivers continued that last year until it was no longer viable. The disastrous trade value aside they are probably better off that the players and Doc finally broke character, because the fantasy - one I certainly shared - that he could grow (both on and off the court) over the next 2-3 seasons is clearly just that, at least in Philly. Right now it's hard to even imagine anything working out for him on another team if it's not the perfect situation. Which is also still the big x factor in a trade if they do somehow get past this toxicity - that dude doesn't want to play for Washington or Portland (though it's close enough to LA I suppose) or Minnesota. If he gets out he'll probably be traded again within a year (or it has to be multi-team).
In The Athletic Bodner and Hoffman predicted he wouldn't be traded until 2022 which seems an easy enough assumption at this point (that could mean anything from two weeks after this year's FAs become available to trade deadline to off-season). Hoffman also predicted a 5th or 6th place finish (though that would obviously change if a good enough trade can still be made).