Shrinking greens saves money, so if a course has ever had managers that were looking to save money, shrinkage will likely be present. I was amazed how much the greens shrank at Stone Eagle in the few months it was in limbo with the bank. St Andrews Beach, which also went through bankruptcy, was similarly affected.
I would think it's this, much more than how the course plays. I went thru this a club in GA where I was a longtime member, and fwiw I didn't think it really made the course play more easily at all. There isn't much way that a smaller target is "easier". IMO, this is likely about money one way or the other, either intentionally to cut down on mowing time and/or bentgrass maintenance, or thru lack of resources to keep bermuda grass from intruding into the bent along the fringes.
The vast majority of shots that end up in bunkers didn't get there by rolling off of a green, so I think you can sort of forget that as a reason. So typically a smaller green just means more balls in some degree of rough, rather than on the green. And add to that that bunker shots have a higher probability of getting hung up in the larger fringes and not rolling out, with a longer, more difficult next shot rather than a putt. Likewise, uinless you're playing at Pinehurst #2, shots that are struck well enough to hit the green don't tend to "visit" the green and then leave, only to be stopped from big trouble by the fringe; to the contrary, smaller greens with more fringe make a "green visited in regulation" more likely, not less.