He looks "bad" because Garp was Roger's equal when we thought WB was the only one. In fact, you can now argue Garp is more of a Roger equal than even WB. We were basically lied to by the narrator and Buggy (as we saw with Garling, this is not even an exception at this point though).
Obviously ignoring the fact that those two weren't lackeys and actually finished off WB's captain. While WB is busy playing tsundere underling to Polo Gram.
This is how WB got introduced btw
this flashback was a fall from grace. The expectations for WB are simply higher. Garp is what we thought WB would be when we read MF. That's the issue. Garp legitimately seems more of an equal rival to Roger than WB.