The better player always win overall, they probably don't make that mistake of leaving the 8&9 much in regular 9I don't think it's harder, in fact for good players it's way easier, no need to worry about running out most of the rack and leaving the 8 or 9 for the other guy. Less pressure. In a "real" game you need to actually win the game not just make more shots, especially when giving up a bunch of weight, I have played a lot of matches with like a 6-2 handicap, and seeing a player tap in a 9 or an 8 and 9 hanging for them to get to the hill on one shot is not fun. There is a lot of pressure to play at the top of the game for the better player, except in APA where making the 9 is just a 2 point gain instead of a win. I could let some 3 or 4 make the 9 every time, technically lose every game, but still win because I can outshot them in the rest of the balls made.
I played a doubles event with my son on a tight table, the other players were way worse than us, it was a 5-3 race and we lost hill-hill, because we would run out the rack to the 8 or 9, just barely miss and leave them an easy shot. We made 90% of the shots in the set but they won because the shots they made were the game winning ones that were sitting in pockets for them. With APA rules they would have lost like 60-8 or something. Making the 9 early is not that common in games, a lot more common is leaving the last few balls sitting easy for the opponent.
Having to keep a 3 at bay when your playing to 56 points or so on a bar table is grueling and difficult in its own
From my experiences, lots of opportunities to get out of rythm and in a bad mindset