Honestly, I have thought the same many times - ie just make draft order random draw.
I love the NBA, watch a ton of it, but let's be honest - it's basically rigged. Even more so than MLB I think because the MLB isn't "rigged", it's just structured in such a way that some teams spend 4X more than the cheap teams. You get what you'd expect. With the NBA, superficially everyone's on a level playing field but, in practice, the stars are all going to clump into glamorous big market teams. NBA rosters are very small to begin with and you only need to fill 3 roster slots with the right guys to buy your next championships. Does anyone think the Lakers are one of the best franchises in professional sports? Lol. The Lakers are the Lakers because they are the Lakers. You could build a time machine and randomly reshuffle the last 10 years worth of their draft picks...wanna make any bets as to whether they still end up with LeBron and AD (or comparable talents)? I betcha they do.
And, of course like any sports league, you have a certain % of franchises that are frankly little more than investment vehicles. Realistically, those types of teams are going to use a high draft pick to get a high profile player to boost ticket and merchandise sales for a few years and then ship him off to the Lakers once it comes time to pay up. Before his career's over, what are the odds of Zion winning a championship with the Pelicans vs winning one with the Lakers. He doesn't even play for the Lakers nor do we have any concrete evidence he ever will, but if you gave me that Pelicans or Lakers binary choice, I would take Lakers without even blinking.
Realistically, the draft is already inherently sort of a lottery anyways. Steph, Klay, Draymond - sure Steph and Klay are top half first rounders, but you sure didn't need to tank to get any of those guys. Draymond is a 2nd round afterthought. Luck. Nuggets are sort of GS-lite. Jokic, Murray, MPJ. Again, Murray and MPJ are top half 1st rounders, but certainly didn't tank to get them. Jokic is another afterthought. Luck.
Shit franchises who tank to get their hands on a top 3 pick aren't a threat to the NBA pecking order any more than letting the Lakers have a crack at a top 3 pick after winning it all.
I'm far from an NBA historian, but I'd love to see examples where tanking actually worked. I doubt there are many. And I mean "worked" in the sense that it helped change the fortunes of the franchise long term.