Interestingly, I think this analysis might show the sets format gives the weaker player a better chance (depending on assumptions).
With three sets being equivalent to a single race to 9, if we count the shootout as one rack (consistent with the original assumptions), then the three-sets format has a maximum rack total of 21, whereas a race to 9 is capped at 17.
Similarly, a five-set match has a 35-game max, and a race to 14 has a 27-game max.
In general, a weaker player has a better chance with fewer racks played. Therefore, for any given number of maximum racks, the weaker player should prefer sets. A race to 11 (21 racks max) is "harder" than three races to 4 (also 21 racks max), which is only the same difficulty as a race to 9.
The only caveat is the probability of any given race length. A straight race to 11 is more likely to go 21 racks than the three sets, if for no other reason than a 4-0, 4-1, or 4-2 start means the sets match can't go the maximum number of racks.
I'm guessing Predator knows all this. I think the sets format is designed to keep probabilities close, and expected time close (so, three sets the same as a race to 9 by both measures) while making drama/interest higher than in a straight race. Every rack seems more important to the viewer in sets, and the periodic reset to 0-0 seems to keep the trailing player in the match more.