In message , Tim Roll-Pickering
writes

I suspect that by the time it was built, it was already obvious that
Aldwych would never be more than a rather useless stub.

In which case, a great lack of foresight. Had an extension later become
available then a Waterloo to King's Cross St. Pancras direct route could
have been constructed. (Isn't something similar floating about in current
official long term pipe dreams?) Even just as a reversing bay the line would
have been of some use - what are the current cut-off points for truncated
services on the Picadilly?

If you're referring to reversing points then we have (from east to west)

Oakwood (east to west move only)
Arnos Grove
Wood Green (east to west only)
Kings Cross
Green Park (west to east via Down Street sidings only)
Hyde Park Corner
Barons Court (west to east only)
Hammersmith
Acton Town
Northfields (west to east only)
Boston Manor (west to east only)
Hounslow Central (west to east only)
Hatton Cross (west to east only)
South Harrow
Rayners Lane
Ruislip
Hillingdon (via Uxbridge sidings)

There are also available to us:
Ealing Broadway (west to east)
West kensington (east to west)
in emergencies.
--
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