There used to be TORK, Vidalia, and now Selector seems to be EOL. Why are there now no TOR controllers available? By now, we should have the best TOR controllers ever! Has the development of these been 'discouraged' by unknown or known sources?
One answer is that Tor Launcher, which is a browser extension that's part of Tor Browser, is a Tor controller, and a very popular one: https://gitweb.torproject.org/tor-launcher.git/tree/
For relay operators, the 'arm' controller, which is currently undergoing a rewrite and will emerge as 'nyx', is pretty popular: https://www.torproject.org/projects/arm
You might also enjoy the 'stem' library which can be used to script all sorts of things via your control port: https://stem.torproject.org/
And most recently, check out the blog post on carml: https://blog.torproject.org/blog/exploring-tor-carml
In summary: from the client side, Tor Browser is integrated with a very good controller, and from the relay side, there are plenty of options, plus plenty more work to be done.