Good comp, TP. Bender is definitely a better prospect than Giannis was. But Giannis developed unexpectedly well, in large part because he actually grew, from 6'9 to 6'11. Bender is already 7'1, but his other physical attributes (athleticism, length) aren't as outlier-y as Giannis's were. Giannis also developed legit PG skills including a great handle for a SF, which would have been hard to predict at the time that he was drafted.
The biggest similarity between these guys is youth, and people who are already labeling Bender a bust are WAY too confident in their assessment. Bender has a large range of potential outcomes, but many of them are very very good.