TDLR; Reject modernity, Embrace Empire!
So for the non history guys wondering why this is a big deal 'we already have concrete?' Yes and it can be stronger than Roman concrete but does not have the longevity of roman concrete as look at the amount of Roman architecture still standing when left untouched by humans for thousands of years.
The cause is it's structure, roman concrete has a lot of lime deposits in it. When over time cracks form, when it rains the water reacts with these lime deposits, recrystalise and fill the cracks, essentially self healing the structure. The romans had nanomachines before they were a thing. Near seawater, their structures actually got tougher over time due to exposure to the minerals in the seawater.
So us finally understanding this means we can now create longer lasting and even stronger structures given time. Lets just hope this Roman concrete is ONLY used in ancient, renaissance or gothic architecture and not any of the shit we make nowadays!
Thought this was a fun example of how much studying history is extremely important to improving the current world.
There's a whole industry around restoration and preservation. They're not going to let that go.
Same reason it costs too much to cure disease so all medical efforts are on daily meds and customers for life.