@windowframer your initial post pushes so very many of my buttons and not necessarily in a good way.
let me explain why.
first of all, if you think politics are linear, who is to the right and who to the left really does depend on where you draw the line in your mind, that indicates the centre. That line can, and does change. Thatcher moved the line more to the right, hence New Labour. And on it goes. It seems to me that the ruling party at the time redraws the line. So Cameron was left of thatcher, then May was right of him, Johnson to the right of May (except socially, where he seemed quite liberal, sadly) and Sunak to the right of May (I exclude Truss as she seemed to me to be off the scale).
If you think of political opinion as circular, then the very far right and far left can, at times, seem almost inseparable. Some Trotskyist became Stalanist who can be seen as closer to Nazis than most other groups. See Russia.
When voting, I tend to go for a group who can realistically get into power and who put forward ideas that are better than (maybe not perfect, just better) the others.
I believe that we shouldn't let be "better" be the enemy of "perfect".
Sorry for the diatribe, I did warn you I'd had buttons pushed. Political theory is an interest of mine, despite having no formal education in it.