Sports Illustrated’s circulation peaked 30 years ago and has been declining ever since. In 2018 it went biweekly and in 2020 it went monthly. Total annual circulation has fallen off a cliff leading to its demise in 2023..
When SI started up, it was one of the few sources of real sports reporting. TV broadcast a smallish number of sports events and that was that.
But then came ESPN and then the web, which combined to saturate the public with sports and sports commentary. There wasn’t a whole lot of room left for week-old reporting that was stale by the time it landed in your mailbox. That’s all against a backdrop of general interest magazines dying off. Magazines are in trouble generally and the sports commentary market is wildly oversaturated.