Well, not in the beefy sense. But just modern sports seem to focus lot more on weights and strength (not just bowlers, but batsmen as well, wasn't hinting Gill/Thakur are muscular looking either )
Also, wasn't saying this is cause of the issue but just wondering if this could be related in any way, I believe reading something along those lines before but can't remember where it was.
I think you have lost some of us in the point you are trying to make, bowlers modern day or way back havnt been particularly 'muscular' . They all work on strength and core strength more so today, most of them do weights but I think it's only part of their training.
The only bowler which springs to mind for England who had a lot of muscle mass was Chris Tremlett.
I've seen him up close and he is the the biggest human I've ever seen. I believe he now runs a body building company and is a body builder himself.
He was,when I saw him for England,absolutely massive in height and width. Not someone to have an argument with.