So long as great and elite play exists at a faster pace, this debunks slow play as causative since it isn't exclusive to it.
You are ignoring that regardless of the era you look at, the speed demons weren't all clumped at the top. In fact what you see is more of the opposite, where the top ranks would tend to consist more of the slow to moderate paced players for the era. This is pretty telling when you give it some honest thought. Go watch Efren again sometime as just one example, he was was no speed demon to say the least, and few of the players at the top, comparatively, were. The reason that is what you tend to see is because fast play is detrimental to being able to play the very best that your abilities allow for.
You are also ignoring that pretty much without exception when a fast player slowed down, their game improved (Shaw, Woodward, and you could go on and on and I can't think of a single exception). Yes there are guys like Shaw and Woodward who play great fast, but they play even better when they slow down. Yes Strickland played great fast, but he would have been even better had he slowed down. He played great in spite of being so fast, not because of it. Again, its pretty telling that the game of a fast player improves when they slow down every time when they give it a fair chance.
Aside from it just being common sense, the evidence is overwhelming that a fast game does not allow for the very best possible pool to be played. It can still allow for a fantastic game to be played, but not the best possible game, and who would knowingly and intentionally choose to play at less than their full potential? Nobody. The only reason guys like Strickland and Butera (and yourself for that matter) and such never slowed down is because they simply never bought into the truth that it would improve their play and so they were never willing to give it a fair chance. More and more of the players of today know better though--the proof is out there if you look with an open mind--which is why pool has and will continue to trend slower with time.
There was no shortage of rack running power in the past. These guys used to string many racks together. The previous gen players were able to process the table visually and make shot and position decisions faster and still get the same results. 6 and 7 packs were done by guys in the 1970's and 1980's too.
6 and 7 packs were actually pretty rare back then too, but they occur today at least as often, actually more I think. What you are ignoring though is that the equipment is MUCH tougher today, like not even close. If today's players went back back to the equipment of the 70's and 80's they wouldn't miss for three weeks.
Even Buddy Hall played faster than most of these guys, and none of these guys plays better position play than he did in his prime.
You have what I'll call a comparison bias, were you tend to see someone as being even better than they actually were because of how good they were compared to their peers at the time. Hall played fantastic shape, especially for the time, but the best players of today play as good or a little better shape, and they do it on much tougher equipment. Another thing you have to keep in mind is that the bucket pockets of yesteryear made playing shape much easier because you had a lot more pocket you could cheat, and because you could devote more of your focus to position portion of the shot since the pockets were so much bigger and more forgiving and required so much less precision to make balls.
To be clear, the slow pokes today don't have a longer or excessive warm up stroke routine once they are down on the table.
I think this has slowed down too, although the slowing is certainly more significant prior to getting down on the shot.
The slowness is in the pre-shot routine. They walk around the table excessively. They repeatedly check angles they've already checked. They keep reassessing patterns even when they didn't get out of line. In other words, after an initial assessment to begin a pattern, they haven't got out of line requiring a plan-B or improvise or change of plan, they do a whole full reassessment.
This does two things. First, it allows them to occasionally spot a slightly better shot, strategical play, positional route, etc. They may only spot something that is 5 or 10% better, and it may only happen once or twice in a race to 9, but those occasional and incremental improvements make a difference. Think about how often a single shot ends up being a game changer, or just how often it is just a shot or two that made the difference in who won or lost a set. The second thing it does is that it allows them to get their mind into the most committed and focused state possible prior to the shot. Again, this might only save one or two mistakes a set, but one or two mistakes a set is very often the difference between a win and a loss. Anybody that doesn't believe playing slower will allow you to spot a better shot on occasion or prevent a mistake on occasion than what playing fast allows for simply hasn't tried it for long enough to give it a fair chance and/or just has a self imposed mental block against it.
I think people like you that hang on to the belief that you can play just as good or better fast as you can slow do so because that is what you
want to believe, and you want to believe that because pool is so much more fun for you to watch and even play that way. You certainly can't be blamed for those preferences, but the evidence is pretty darn clear that your fullest potential can only be unlocked with slower more deliberate play, and as a result that is the style of play that is going to tend to end up at the top of the heap in the pro ranks, and they aren't going to be voluntarily changing it, to their own detriment, simply because it isn't to your or my most ideal viewing pleasure.