The 2.7% figure is presumably based on the assumption that all current passengers would have continued travelling had fares risen? This almost certainly wouldn't have been the case although quantifying the actual effects of fare changes is hard enough in normal times. Covid has made that even harder.
Regarding Crossrail cost over runs. I see this is often now being quoted against the figure of £14.8 billion, this was actually a reduction from an earlier figure of 15.9. The cut was made in 2010 as part of the government's 'austerity' measures and was quite clearly never realistic with the benefit of hindsight. Final cost quoted at £18.9 billion. It's a big number but in percentage terms the cost over run probably isn't that bad compared to some other projects world wide. I suggest reading up about Berlin airport if you want to see what a cost over run can really look like, nearly triple the original budget!
Regarding Crossrail cost over runs. I see this is often now being quoted against the figure of £14.8 billion, this was actually a reduction from an earlier figure of 15.9. The cut was made in 2010 as part of the government's 'austerity' measures and was quite clearly never realistic with the benefit of hindsight. Final cost quoted at £18.9 billion. It's a big number but in percentage terms the cost over run probably isn't that bad compared to some other projects world wide. I suggest reading up about Berlin airport if you want to see what a cost over run can really look like, nearly triple the original budget!