… unless they are rusted out. (mine was, and a couple grand later, the plumbers had a new line put in. they bluestaked everything, and IIRC subbed out the labor to dig the trench and remove what was left of the old line. )
as far as digging a trench to get fiber to my house? I’ll sub that one out and get it done right the first time.
I dunno, i’d guess they are banking that customers aren’t savvy enough to ask/push for alternatives. Monopolies and whatnot. Here in my area there’s a few other gas utilities looking to get a slice of the pie so we have plenty of incentives to try to work with customers and do right by them, there are still situations where installs are inherently expensive though and i always feel bad turning customers away or giving them the bad news on the estimate.