In some cases air will be faster than trains, and in some cases trains will be faster than air travel. I don't think anyone disputes this. It's certainly not true that you just add one new line to connect a location to a rail network and magically get all the promised benefits and more, but see:

> There may be reasons to add or update infrastucture ...

As long as we're talking in abstract we can construct scenarios where one is faster or better. However my read the original comment was that that adding a new connection involves adding new infrastructure, which isn't always true.