Other losers are London Bridge bound passengers from Wandsworth Road
and Denmark Hill, who will lose a direct service to London Bridge.
They will be able to change at Peckham Rye (same platform interchange
for ELLX services, different platform for rerouted SLL to Bellingham
services), or travel to Canada Water on the ELLX for interchange with
the Jubilee line - though that really is the long way around!
I don't think its appropriate to believe that most people going to
London Bridge go there specifically, rather than just because its a
connecting point on a longer journey to the city, or via the tube. Of
course there will always be some people going to London Bridge itself,
much as there are some people who actually go to Peckham Rye for its
own sake, but for those travelling via the tube, isn't it more
efficient to use the ELLX, where they can change directly onto the
Jubilee at Canada Water, the district line at Whitechapel, or the
Central line at Shoreditch.

I imagine the number of Wandsworth Road to LB pax isn't great.
I imagine that Wandsworth Road --(walk)-- Battersea whatever/Vauxhall
--(NR)-- Waterloo --(Jubilee)-- London Bridge is a lot faster and
more frequent than going via the South London Lines

Of course they can still get the first train and change at Peckham
Rye, or indeed the first train to Clapham High Street and change for
the Northern line.
Or change at Canada Water and get the Jubilee line.

Most opposition to changes like these seems to be idiological. Its
more "better transport links = gentrification = enemies of the working
class" than "change = worse transport".