The disagreement is not that autocomplete with a remote backend is a keylogger, that's factual. It's about calling it malware right?
Because you seem to be asserting what "everyone else" thinks.
If I ask non-technical people about this autocomplete feature and whether they would like to disable it (assuming they have this option), after explaining it sends every keystroke to Google, they (generally) will reluctantly agree to have it enabled, why?
It's not because they believe sending every keystroke to Google is a super reasonable sacrifice for having the benefit of autocomplete on search queries.
No, ask them, they will invariably sigh "Well, Google knows everything about me already, anyway, so ...".
That's NOT the reasoning of someone making a well thought-out decision, it's the reasoning of someone beaten into submission. And we know this is true, because we feel it too, every time you read a comment about somebody trying to escape the Google Ecosystem, but not yet having a satisfying replacement for this one service .. You don't get to make a fair choice about it.
That is why they say Google mistreats their users, because they made them give up, not just giving up their privacy, but giving up on their belief they even have a choice about it.