> Basically boils down to: If politicians get to call the shots in any way, it's going to run way over budget. Pretty much every single time.

So it’s not a surprise that we find counter examples in strong democracies. The Gotthard Basistunnel was build faster than projected and about 30% cheaper [1].

[1] https://en.m.wikipedia.org/wiki/Gotthard_Base_Tunnel