Sixers fans must be ecstatic to be rid of him and no longer have him be their problem. At least Joe Barry Carroll was a somewhat useful player in the league for a few years (and an all-star once).
What are the top 5 biggest
#1-overall-pick busts of the post-merger era? Not many such players failed to become all-NBA, and of course over half are hall of famers. Contenders include:
1972: LaRue Martin, Portland Trail Blazers - 4 years, 271 games played (pre-merger, slightly)
1989: Pervis "Out-of-Service" Ellison, Sacramento Kings - 11 years, 474 games played (245 started)
1998: Michael Olowokandi, LA Clippers - 10 years, 500 games played (393 started)
2001: Kwame Brown, Washington Wizards - 12 years, 607 games played (281 started)
2006: Andrea Bargnani, Toronto Raptors - 10 years, 550 games played (377 started)
2007: Greg Oden, Portland Trail Blazers - 3 years, 105 games played (66 started)
2013: Anthony Bennett, Cleveland Cavaliers - 4 years, 151 games played (4 started)
2017: Markelle Fultz, Philadelphia 76ers - 2 years, 33 games (15 started)
I think you'd have to put Fultz on track to easily be in the top 5 worst, and could well challenge Oden and Bennett for top honors.