I hate to say it but that article is mostly rubbish. In my mid to late twenties I was a fairly grinding, limited batter and rarely, if ever hit a six (clearing the boundary). Changes to bat technology (the willow is pressed much more lightly) mean that last year, as an old man playing for the first time in 15 years (with my 15 year old son, who had started to play adult cricket) I hit more sixes than in any season when I played even reasonably seriously. If anything, I'd say changes in bat technology have made more difference to me in 15 years than changes in golf ball technology.
Also, pads and gloves are lighter and better and 40 years ago nobody ever batted in a helmet. So I'm sorry but that article is just rubbish.