Earlier quoted context omitted.
That's the entire point of The Boring Company. It's way more expensive than anyone expects. That's the problem they are trying to solve. The entire goal is "serious advances in rock boring techniques". That may be a lofty goal, but at least the message I got is that it is the one they want to reach.
>> "(personal opinion: there are none coming)" Former tunnel boring engineer here. There is a ton of room for innovation around tunnel boring machines built by the major manufacturers (primarily Herrenknecht and Robbins), around reliability, durability, ease of serviceability etc. I cannot emphasize enough how modern TBM's require an unbelievable amount of engineering attention, repair labor, spare parts infrastructu…
I know Cincinnati's subway failed because of some bad tunnelling that caused foundations to sink .. well that and the great depression. If they had started earlier or designed it better, Cincinnati could have a Chicago like transit system today. Unfortunately it took them years to get a tram and there are people still trying to shut that down instead of expand it! Unbelievable.
I know in Seattle, many of the tunnels (like to Northgate/UDistrict) have actually been fully bored. The new stations are still not due to open for a few years, mostly because the majority of time isn't spend on the tunnels, but installing track, electrics and building the underground rail stations.