I think it's all relative tbh. E.g in Nazi Germany the only centrist position would be slightly less fascist than the existing society, whereas our "centrist" position would seem like far-leftism in their society.

(If you think religion is politics): At different points in hapistory, some things are off the table, like atheism, paganism. I heard Soviet Russia outlawed religion, too - so even Christianity, in some places at some points, is off the table

New technology also makes some positions more palatable, or even possible, than others.

• If we only knew how to produce consumer scale electricity from coal combustion, any talks of reducing climate change would be seen as regressive; in modern reality, we hope to fix the climate by adopting newer and more elegant technologies to phase out old ones, so it is a progressive position.
• some historians argue that slavery was literally more palatable to historical people than modern ones, who were living in a world without industrialisation, hence more manpower was needed to do all manner of "basic" things like large scale agriculture.

Hope nothing I've said offends, this is supposed to be a neutral comment and not further an agenda.