This. China built that supercomputer as a pure PR/face move. It isn't very interesting otherwise, and the west stopped building those kinds of things a long time ago because it moved on to more detached distributed computing.
You need to look deeper into the latest system. It's not a pr machine. Even the pervious one tianhe-2 isn't. If you think it is, you're looking at the wrong sources.
And no, we have not moved away from supercomputers or building bigger ones.