I think the majority are using 3.x for new projects? Of course there's still a lot of 2.x around.
A lot of us who came to Python late have only ever used 3.
I can't imagine the horror of dealing with multiple charsets and bytes in 2.x
You don't really have to deal with bytes in py2. That's part of the problem.
You have to. And even some http libs only use Bytes in py3.
Dealing with Sockets also only works without unicode. Thats just horrible.
3years ago I would probably argue that you should just use Python 2.X. But most packages you will use are now ported to Python 3.
One issue is that almost every google search for documentation points to the 2.x version, sometimes even if you search for Python 3 meaning you have to manually find the dropdown and switch to a new version. I imagine this is cumbersome for many new developers.
It's all about what OSs ship with, and we're getting to the point where Python 3.x is the default.