You know, I came in here ready to blast this guy for trying to collect page views by being controversial. Then I stopped to think about it, and... it really isn't all that controversial.
Who is honestly playing better than Giannis right now? MCW obviously. Burke, kinda. Tim Hardaway Jr here lately. Oladipo. But with the possible exception of Dipo, Giannis's potential just blows all of those players away (and I suspect that MCW is a bit of a system guy in Philly - he's good, but he's also in a very favorable situation).
Then you have other 'potential' guys. Noel. Mason Plumlee, Steven Adams. Ben McLemore. KCP. Alex Len. If you include Giannis in that group, I think the only one with greater potential is Noel, who is recovering from a knee injury.
So, sitting here with my eight-months-ago hindsight goggles on, I can't in full honesty say that taking him first is completely indefensible knowing what we know now. I wouldn't do it - I'd take Oladipo and Noel ahead of him at the very least, and others depending on team need - but I can at least see the thought process that leads you to Antetokounmpo. So if you're sitting on the #1 pick, you're scared by Noel's injury, you don't need Oladipo... maybe then you trade the pick consider Giannis.