Have a system of technologies that can be achieved in a non-linear fashion through their associated societal factors. So you could be working towards dozens of technologies at once passively, and semi-actively by guiding your society in new developments in relevant sectors. This will allow some countries to specialize or always be at the forefront of a given sector (shipbuilding/warfare are some easy examples).

It doesn't make sense that a landlocked nation can build the most advanced ships as soon as they conquer a single port, as long as they've kept up in dip tech.

A very rudimentary system would be how institutions work and have them replace technology entirely. It's just that you'll need to be quite innovative with the UI to make having hundreds of technologies/traditions/ideas be somewhat manageable while still allowing some player interaction.

This is more simulation as opposed to the linear board game approach.