This trade looks INSANE, but for a fun point of view it actually makes sense and heres why.
Thunders Side: Giannis has been top three in mvp voting for MANY years, his production in the playoffs has been insane and yet they're still losing due to the poor talent around him. The Thunder would be a dream place for Giannis to play at. Every position can shoot and even after this trade they're still very deep. They have rookie Nikola topic and this trade frees more rotational time for him and guys like Aj mitchell as well. This gives them a powerhouse of a big 4, Giannis, Shai, Chet, and Jdub. They have Lu dort who arguably should've been a finalist for DPOY. This team would RUN the NBA.
Rockets Side: They're still incredibly young and they lack a real point guard, Fred Vanvleet is okay but he's super inconsistent. This team needs that true vet of a point guard to take them to the next level. He fits in perfect with guys like Amen, Tari, Jabari, and Sengun.
Bucks Sides: This is just a hard reset where they get as much as possible in return, they get a really good 5 man that they can use and even decide to flip him for more draft capital in the deadline of the season. They get the rise of Aaron Wiggins who has been super good for the thunder, they take the chance of Reed Sheppard who hasn't really got to play much his rookie year but can thrive in a system where he plays 20-25 mins his sophomore year behind Fred (if they lose games they can end up starting Reed). Cam Whitemore and Isaiah Joe are both talented wings in this league. This can give them a lot of flexibility giving the fact Fred will be a expiring contract and they can make some big moves with this roster.