I reckon over their whole career, Brett has been the better (not to do a dis-service to Josh who has also been very very good).
I’d have Brett down as a definite Hall of Fame inductee - sure there might be some wingers who were faster or bigger/stronger, basically more physically gifted, but I genuinely don’t think you’ll find a winger who played at such a high standard so consistently. I can’t think of him ever having gone through a poor patch, and whilst he might not have a massive highlights reel of winning games pretty much on his own (like say a Meninga or Johns), the difference between his best and worst games will be much lower than almost any in the games history - I reckon he’d score at least an 8/10 week in, week out. He’s great defensively and an absolute weapon finisher.
If you were picking an all time fantasy team that was actually built for a proper season, rather than just highlights reel stuff, I think he’d be in my team.
Will there ever be a winger made an immortal in the future? I doubt it as they just don’t get to own games too often - but if you were doing positional immortals, he’d have to be in the conversation.