looking back at the past finals teams, not even just the ones that have won titles
duncan, wade
KD, wade
dirk, wade
kobe, pierce
kobe, dwight
kobe, pierce
lebron, duncan
wade, dirk
every one of these teams had a hall of famer that they drafted
Yeah but look at the players you are mentioning. Generational, franchise changing talents. They do not come around that often. Most teams don't get this lucky. I think great drafting is a plus but not a necessity. The odds of winning in the NBA are so low that to me it's not even worth tanking. Like you just mentioned, past champions have drafted Hall of Famers. How fortunate are you going to be to get a hall of famer? If you're really lucky, most of the times you'll get a player that at best gets you to the 2nd round. Only 4 teams every year make it past the 2nd round anyway.
So, the notion of being a 1 to 2 round team and bouncing being mediocre may be true, but it's also the likelihood for most teams, regardless of the way you draft. (Unless you hit a home run like Lebron, or Tim Duncan) This is why I'm against tanking and would rather be average than horrible because the incentives for being horrible aren't great at all. Unless you get a generational talent, the best you're probably going to be is a 2nd round and done team.