In message , Sir Benjamin Nunn
writes

Or almost anywhere on the London Bridge / Victoria / Clapham Junction lines.
or Tramlink.

London Bridge to Gatwick is 29 minutes.

London Bridge to LCY will be 24 minutes (allowing 5 minutes for the
change at Canning Town).

Obviously, if you are nearer to a Brighton-line station then Gatwick
will be the better option.

And thus is vastly more useful for people who are visiting London (and
tending to stay in the centre) rather than those who already live here and
are travelling to Europe.

It depends entirely on where such people live. If they live near Luton,
Stansted or Heathrow, any of those are likely to be a better option than
London City or Gatwick.

People who work in the City commute from a vast range of different places
from all directions, varied distances and travelling times from the centre,
and an airport 22 minutes East of Bank is therefore only of convenience to a
limited subset of them.

Exactly. That's why London has 5 airports - to cater for as many subsets
as possible. LCY will get increasingly better connected (even to South
London) in a few years time, when the branch is extended south to
Woolwich Arsenal and north to Stratford International. Even more so when
Crossrail is built.

If City Airport was actually 22 minutes West of Holborn, 22 minutes North of
Euston, or 22 minutes South of Embankment, the impact on visitors to Central
London would be minimal, but the subset of Londoners that the airport
happened to benefit would be significantly different.

But its not, is it? I can't really see what your point is, other than
the obvious one that different airports are closer to different groups
of people in the London area.

--
Paul Terry