I have never seen an xcancel captcha..
Neither do I - just the usual "verifying your request" screen: https://i.ibb.co/MyWRVtFj/xc.jpg
Which is a PoW CAPTCHA, but a CAPTCHA nonetheless.
However, if your JS is disabled (or if you're running LibreJS), you do get redirected to a CAPTCHA which only works sometimes.