Very interesting thread, regarding not only what happened in the past but what is the future going to be.
Handicapping is one major factor that influenced changes in Pool, change of rules and spread of knowlegde being the two other major ones along with increase in recreation possibilities in the last two decades.
It is true that with modern formats players have to be "stronger" mentally, or at least more patient since alternate breaks do not allow rhythm build up and thus the confidence factor between the better player and the weaker one is minimized, even more when there is handicap involved. Although some of the better players (the ones that have adapted) still survive in the long run, the weaker ones don't have to do the kind of effort needed in the past in order to beat them. The new players have no images of the past so they are already coming into the game in that kind of thinking.
Back in the old days pressure factor was different, you knew that if you missed a shot you could be easily sitting in your chair for 20min, only to come back at the table for trying to pull out a difficult resafe, meaning that could be your last visit there. So in order to get to win you had to really work on your game, there was no easy way to get by the shots needed unless you knew exactly what you were doing, no second chances were available since you wouldn't be breaking next rack even if you lost the frame. As in all things that require hard work Pool had more respect, the pros had more respect, Pool was really a sport in tournament manner that promoted excellence.
Gambling was always there, in any kind of form, but gambling has always been an almost completely separate world in Pool, no need to get into that.
What happened then, besides more reacreation, that led to format changes?
The best players performed better constantly, and unfortunately there was no good spread of prize money so the less good players (which were still very good players) could not follow the tournaments anymore, the same applies for the weaker ones which were still coming to play for the fun of it.
So format changes were applied and participations increased once more.
But let's be honest, there may be more "game players today" since anyone can beat anyone but less "students of the game-athletes" compared to the past. So yes, maybe the game got better, not sure about the sport though.. Proof? Look at Mosconi cup. Most of the European teams come from the "student of sport era", while the opposite stands for the USA team which is trying to go back to that philosophy now. Even the US team members which also come from the "student of sport era" still stand out "like a fly in milk" compared to others, and any of the young players which is of that mentality is still definitely better.
There is a great responsibility in the market side of it, promoters, companies, club owners. While their work cannot be ignored, they haven't done what was supposed to do to promote Pool as a sport. The format changes suited them fine since their casual customer-game players have increased without any significant effort. The players on the other hand got used to winning situations without the hard personal work required in the past, and generally most players of all times played Pool without thinking about next day. There was also no real effort to distinguish tournament play and market profit, and since there was no real hard work kind of thinking in that part too, tournament play was adapted to immediate profit. The results have not settled yet, and it's kind of a relative to many factors situation, but nobody is certain what will be the case in a few years.
So, in making a summary on this, yes, changes have helped the game, but damaged the sport.
And hell, the sport era was way more beautiful than today..
Petros