Anyone can design a bridge that holds up. Romans did it millenia ago.

Engineering is designing a bridge that holds up to a certain load, with the least amount of material and/or cost. FEM gives you tighter bounds on that.

The average age of a bridge in the US is about 40-50 years old and the title of the article has "80 years of FEM".

https://www.infrastructurereportcard.org/wp-content/uploads/...

I'd posit a large fraction were designed with FEM.

FEM runs on the same math and theories those bridges were designed on on paper.