You can't win if you consistently draft in the 5-10 range. All you do is keep yourself drafting in the 5-10 range forever.
Sure nobody can win if your own pick is consistently landing in 5-10 (because that means you continually suck). But you can draft in 5-10 and turn your team around. This idea that only way to win is to draft high is nonsense. Look at the champions, these aren't teams built off successfully drafting higher than 5.
Bucks ('21), Raptors ('19), Warriors ('15, '17-'18), Heat ('06, '12-'13), Mavericks ('11), Lakers ('09-'10), Celtics ('08), Pistons ('04).
Who are the best teams based on last season:
Sixers - high picks
Nets - desirable destination
Bucks - smart/lucky drafting
Knicks - high pick, free agents off the trash heap after being scorned by top free agents
Hawks - traded away their top pick to move down in the draft
Heat - desirable destination signing free agents, smart drafting/signing
Jazz - smart drafting
Suns - smart drafting, trades, top pick
Denver - smart/lucky drafting
LAC - desirable destination
DAL - smart drafting/trades
POR - smart drafting
LAL - desirable destination + high picks to trade for superstar demanding to be traded there
GS - smart drafting
MEM - high picks
Looks like there's a whole lot of ways to win, and any team can win with smart drafting/trading.
The last guy picked higher than 5 that significantly contributed to the team that drafted them winning a championship is who, Kyrie in '11 and then Duncan in '97? That's a pretty short list. Then we have to go back another 10 years before it happens again (David Robinson ('87) and that took 12 years to pay off.
High draft picks is the only way to win is outdated thinking, especially in the player empowerment era.
High draft picks being the easiest way to win is arguable, but plenty of examples of why it's far from full proof and may be better to go other routes.