Fully agree. The extreme left barely exists in the UK, Labour are perhaps a little right of centre, and the extreme right is all too well—funded and high-profile.
(Thought I was adding this to my previous post, but in fact I was replying). I think part of the mechanism here is the normalisation of Trump. An authoritarian/trending fascist US President is continuously reported as mostly business-as-usual, and this inevitably shifts the discourse rightwards.