Haliburton aside, look at some of the picks immediately after the Wiz picks. Guys that are strong two way players or emerging stars or in some cases already stars. The Wiz never hit on these picks. When you are a bad team, meh picks don't help move the needle at all.
Rui wasn't very good here. Had a few nice moments and some flashes but inconsistent and missed a lot of time. Deni is okay and has gotten better this season, but doesn't have a high ceiling despite what Deni-stans think. (the most annoying fanbase in Wiz history) Corey is a one dimensional player, which isn't a recipe for a contending team let alone when a team is bad and needs starting caliber players. If he isn't scoring, he's not contributing. Johnny Davis, enough said cause I don't want to pile on.
Ultimately, these draft picks didn't improve the team in any meaningful way, hence the terrible draft record.