Don't feel too badly....as a Legend with a 69.99 average, I sometimes wonder the same as you. I've seen WGT members put up 17 birdies on Olympic.....which boggles my mind.
But, I think if you'll look at the STATS and AWARDS section of the BEST Legends & Tour Legends.....you'll most likely see they have hit over 1,200 ranked rounds....many have hit between 2,000 & 4,000. I even have a WGT friend who has hit 14,500+ rounds. I only have hit about 700 rounds.....and I have a LOT of improvements to make in ALL areas of my game. So, practice....and just continuing to try to improve each week.....you'll see results. But, you can't expect to hit scores below 60 until you've played a TON of WGT golf. Although, I do know of one WGT member who went from HACK to LEGEND in 6 weeks....but, don't ask me how he did it. And there are many Legends with LESS than 500 ranked rounds....not sure HOW they accomplished that goal so quickly.
I know some members (take notes)...on various courses...and when they are playing CTTH. I believe the putting aspect is the most difficult - I can't even putt on greens now unless they are "Tournament speed"......but, my putting sux...the BEST players have a (1 putt average around 50%).....and that makes a HUGE difference in how you score.
Before I played any Tournaments, I spent 4 or 5 months playing CTTH & ranked rounds on my own...just trying to learn how to use the various clubs and get to know all of the holes on all of the courses. Even now, I tend to play Tournaments that have UNLIMITED PLAY....so, I can play more than once, to improve my score and standings on the Leaderboard. I have learned that upgrading to good clubs & better balls has been helpful to me......STILL, have to learn HOW to best use those clubs in all areas of the game.
Be sure to watch ALL of the WGT videos....and there's always good information you can pick up from long time WGT members here in the Forum Section.
I took a look at your Profile....your STATS are pretty darn good. Hey, you have 1 more Hole In One in ranked play than me.....and you have a "double eagle"...I'm STILL looking for my 1st one of those. Hang in there...you will improve. I NEVER thought I'd make it to the Legend Tier...and I did....but, I definitely don't consider myself one of the BETTER Legends....I need to hit another 1,000 to 2,000 rounds in order to improve my game!
GOOD LUCK!
Bob