1953 Rolex Magazine Explorer Model Introduction Ad
The Rolex Explorer ad pictured above first appeared in the Geographic Magazine in 1953. Notice how primitive the early Rolex bracelet was in the sense it lacked Solid End Links (SOL).
At the time, 36MM was a larger size. If you fast-forward 71 years later to 2023, the bottom line is that human's have grown MUCH larger, and thus it makes perfect sense the Rolex has been modernized. This is not the first time Rolex upsized the Explorer as they came out with a 39MM model years ago, but it's scaling was off as Adrian Barker discusses in his excellent video seen below.
Don't worry, Rolex is still making the 36MM Explorer Model, so if you prefer a smaller size you will maintain this option. You can learn much more by checking out my story titled, The Complete History: Rolex Conquers Mount Everest.