Defining ideology could be a whole series of books lol I personally prefer to define ideology as method, and given just that definition you are right that Plato wouldn’t be the founder, but knowledge and reason as method towards utopia is all Plato and a new formation of ideology.

So, when he talks about love of knowledge, I think he really meant method and not knowledge itself.

Socrates, as read through Plato, could be claimed as the founder I guess but I think he asked too many questions to be called an ideologue and a slave to method and I don’t trust Plato’s filtering of Socrates.

I’ll try and find a source, could easily be Plato and I’m just a hater. I can’t find the link I saw that said Pythagoras said it.