I think we can read between the lines here.

https://ppforum.ca/wp-content/uploads/2019/01/Canadas-Infrastructure-Revival-PPF-JAN2019-EN.pdf

"P3s have never driven the degree of innovation envisaged because governments remain averse to being too cutting-edge for fear of getting things wildly wrong.

What if governments didn’t just sign contracts to build projects that they specify, but also opened the infrastructure field entirely, by asking any and all comers to provide new ideas about what should be built and how it should be built?

As one infrastructure expert put it: solicited proposals result in “small ‘i’ innovation,” while unsolicited proposals will result in “big ‘I’ innovation.”