I don't think you played particularly poorly here, but there were some matchup-specific problems (besides it being in ROB's favor in general imo). Mainly it was just being too aggressive and linear in your approach; you can't really do that with ROB because his arsenal will always outrange you. If you aren't weaving to space and bait options, you aren't going to be taking full advantage of Jiggs' aerial game, and a character with great aerial range like ROB is just going to highlight that. A lot of your damage was just ROB stuff that punished your approach.
Second, you basically ignored the gyro the whole time, which is not the way to go. Gyro can be fussy to pick up grounded at times but if you can take control of the gyro it greatly hinders ROB's options for keeping you away in the air and gives you that power instead. It keeps them guessing on when you're going to zoom in, and since he only has aerials and lasers to keep you out in the air (which aren't fast enough to catch a well-timed gyro throw) he has to land and rely on shield a lot more. Meanwhile, a thrown gyro (not z-dropped, for some reason) and Pound instabreaks his shield.
Game 2 a commentator pointed out that ROB almost ran out of gas. Not sure if you were trying to capitalize when you got hit by the upair but that should've been the intention at that point since he was overextending. Also about those upairs, I'm pretty sure you can single jump and airdodge off the ledge if you're expecting it and just bair them as you descend since they're vulnerable from the side as long as you can get down there. Would like to test.