Not the algorithms OP is referring to. Those are black-box learning models which discover what to recommend based on - in the case of Facebook, YouTube and Twitter - what generates the most advertising revenue.

The "particular values, agendas and biases" you're referring to are just advertising revenue, not some political bias installed by the developer. If you WANT to believe there are such developers working at those companies, I can't stop you. But the evidence isn't really there. Make some friends who work at those companies and see what you can find out from the people who actually develop the tools you're accusing of having such political bias in.

Now, if we are talking about political bias in these platforms' policies, you might have something.