But I believe the gatekeepers of AI models will manipulate the algorithms to edit out anything they disagree with whilst promoting their agenda

This reads like a conspiracy theory to me, complete with assumption-laden words and unsupported accusations like "gatekeepers", "manipulate", and "promoting their agenda".

Having worked at more than one of these companies, what actually happens is that some part of the team picks a "user engagement metric" to care about, like "total time spent on the website" or "total value of products purchased through the website", then everyone in the team puts a lot of time and effort into writing and testing out changes to the algorithms with the aim of finding ways to make that metric go up, even by 0.1% for a project that took several people a month. Then, after a few years, people ask "why has our website turned into a toxic cesspool?", until someone points out that myopically pushing that one metric as hard as possible turns out to have unfortunate unanticipated side effects. For example, maybe the most effective way to get people to spend more time on the website turned out to be measures that had the net side-effect of promoting conspiracy theory nutcase interactions (in many flavors, thus appealing to many different subsets of users) over reasonable discussions.

So the 'agenda' here is just "make a profit", not "spread conspiracy theories" or "nefariously promote Liberal opinions", and the methods used don't even always do a good job at making a profit. The message here is that large organizations with a lot of power are stupider, more bureaucratic and more shortsighted than you appear to think they are.

Yes, most software engineers are university educated, and thus, like other well-educated people, tend, in the modern political environment, to be more liberal than an overall population that also includes people who are not university educated. However, we're strongly encouraged to remember that our users are more diverse than we are, don't all think or believe or act like us, to "think like the users", and not to encode personal political opinions into the algorithms.