In terms of sheer numbers, I would guess that at least a plurality of websites are running old versions of PHP and are released via FTP. But I don't think that'

In terms of sheer numbers, I would guess that at least a plurality of websites are running old versions of PHP and are released via FTP. But I don't think that's really meaningful or interesting to worry about, since those services aren't even considering the tooling decisions we're talking about.