Yeah, even if a team was guaranteed to make the Final Four, assuming a 50/50 shot of winning each of the Final Four and championship games would make a team a 25% chance of winning the title.
For the fun of it, say a 1-seed has the following probabilities of winning given that they make each round:
1st round: 100%
2nd round: 90%
Sweet 16: 80%
Elite 8: 70%
Final Four: 60%
Championship: 50%
The probability of that team winning the title is 15.1%.
Even if you assume the following:
1st round: 100%
2nd round: 100%
Sweet 16: 90%
Elite 8: 90%
Final Four: 70%
Championship: 60%
That's a 34.0% chance of winning it all. So even a team that is heavily favored against elite competition would be far from the odds-on favorite.
That being said, let's hope Irving's toe heals, so we can be a bit closer to an odds-on favorite (trying to make my post at least remotely on topic).