What if they included a system like the province development caps on the innovation/tech tree? That way max stats could be limited until certain innovations raise the soft stat cap.
Eyeglasses could raise the cap on learning, the stirrup could raise the soft cap on prowess for people trained in horse riding. Three field crop rotation could raise the soft cap on stewardship. Access to Toledo steel and, later, gunpowder raises the soft cap for martial. Advanced age can reduce some skills, like learning if you don’t have a reading lens, archery prowess declines if you haven’t unlocked the crossbow, and so on.
Certain cultural modifications can make the central Asian plains cultures better on the horse. And so on…
That way, you can add all the artifacts and all the learnings and trainings, but stats have additional soft caps and limitations until the right innovations come along.
It’s a rough idea. I hope the idea is coming across. Real life comes with “logarithmic” s-curve limitations on any “limited resource” effort (like human skills). (There is always a point of diminishing returns.) If the game only captures the early exponential part of a skill system, ignoring the point of diminishing returns, we will always get the “stat bloat”.