What is the benefits of high GT scores(above 110)?

There is zero benefit. 110 is the number recited because that's the minimum to become an officer and for a few other special positions. Most MOS's use other line scores besides GT, but the ones that do use GT, 110 is the max for those.

A higher GT doesn't help you in any way. It can't be viewed by the promotion board. If two people are up for the same job, having the higher GT won't get the job. It won't make you more competitive for promotion or being selected for special assignments or commissioning programs. In fact, most enlisted Soldiers will never need above a 100 GT

There are primarily two reasons:
1) You can choose from more jobs if they happen to have openings.
2) When the time comes you want to change MOS's at the end of your contract you won't have to retake the ASVAB, which at that time if you are still in the Army you'd have to jump through chain of command hoops to get permission to retake it.

higher the score the better your chances for getting better jobs. What's the actual question you want to ask?