This is a really good observation. It's interesting that SS has been producing more offense than 3B since 2024.
It seems like the latest young crop of stars all play middle infield. There are not many high profile 3B debuts of late, certainly not of the level needed to replace aging stars like Arenado, José Ramírez, Bregman, and Manny Machado. Austin Riley isn't that old but his production fell off a cliff.