Comment # 4 on bug 1103320 from Bernhard Wiedemann

Yes, screen -a helps to get TERM=screen again,
including working alt-left in bash
and working remote ssh sessions to older Linuxes.

man screen says
       -a   include all capabilities (with some minor exceptions) in each win-
            dow's termcap, even if screen must redraw parts of the display  in
            order to implement a function.

so is it not default, because there might be expensive features?
Or are there other reasons?

and what is the TERM=screen.xterm supposed to do?

I think, screen.konsole was similarly broken.

/usr/share/terminfo/s/screen.xterm comes from the
terminfo-screen rpm from the ncurses srpm.

But OTOH it is still bad to set TERM=screen.xterm by default
when my remote machine does not have the file.