I'd argue Meta is much worse:
Palantir builds these systems for the US government which is (hopefully) something you can hold accountable / can reasonably trust.
Meta builds these systems for itself to make digital cocaine and sell personal data to profit off everyone (including and moreso primarily the elderly and children). You can't hold them accountable, actually pretty much nobody can hold Zuckerberg accountable.
When Palantir helps USG spy on the planet the primary purpose is defeat enemies + protect assets. When Meta builds these systems the primary purpose is digital cocaine.
Does Palantir collect data or just analyze aggregated purchased data? I'm not familiar with the data collecting SDKs available as I don't whore out myself/my sites like that, so maybe there is a pipe directly from them????
Either way, I'd definitely hold those directly responsible for collecting and selling of the data way worse than those that just make use of a product. It's like the war on drugs where those making say they will make as long as there are people wanting to buy