Plenty of companies don't "need to exist". A company exists because someone decided to start it (usually to make some money) and lasts until someone decides to end it (usually when it stops making money).

If you're asking why Palantir (and Salesforce, Jira, etc) continue to make money despite not having any novel or complex technologies, my experience has been that these are not prerequisites for solving the vast majority of business problems. Usually network effects, customer relationships, brand identity, user interface, inertia, etc are all more important than the technology.

It is not always easy for a technologist to admit, but companies whose ongoing success is primarily due to some sort of (non-UX) technological superiority are the exception rather than the rule.