How far can A Streetcar Named Desire be seen as a tragedy for Blanche and her values or a triumph for Stanley's values or both?

I think that Williams is quite deliberate in concluding
the play in a manner where there are no "winners."  Blanche's institutionalization is
not done for her own welfare, but to consolidate Stanley's own control over his wife,
something that she herself regrets in the end.  Stanley is shown to be driven by power
and whose actions are brutish, revealed in pure atrocity.  Williams is able to show that
the resulting collision of values in the modern setting does not yield a winner, but
rather different shades of loss. Perhaps, Blanche was not made for her particular
setting, but her confinement and ostracizing are shown to not be proportionate
responses.  In the end, the tragedy is for everyone concerned.  Stella understands her
failure and Stanley's failure as a husband.  Blanche is forever confined with her
melancholy, unable to articulate her condition and relegated to silence.  Stanley has
gained control, but the loss of faith from his wife is demonstrative of reflecting power
over nothing.  In the end, Williams' construct of modernity is one where pursuits of
happiness are evident, with happiness being far from it.