Now they have a platform that's hard to replace because the businesses that rely on them are extremely slow to adapt themselves that's the very reason Plantir was able to get into the space.
Most companies like the mentioned Airbus though do nowadays get convinced to do more impactful things, and they do reap the rewards.
It doesn't help that the product has evolved ridiculously over the years. Just in these comments there's people who e.g. worked there in 2016. Productwise they might have well have been at an entirely different company, unless they were on the gov side of things.
In hindsight, the fact that Palatir went to Airbus meant that the fix was in and it was already decided that Boeing was going down. Or for the less cynical, it was Palantir's magic that made Airbus successful and if Boeing were competent they would have hired Palantir.
Going for operation use cases was a huge win. Once novel data existed in the system (rather than just transforms of existing data), it became a lot harder to rip out. That could be as simple as having someone merge records so you know that two companies are actually the same.
Foundry was a really interesting case because it was basically an enterprise ETL platform before those became very popular + a team of people who helped you get data into it. One of the genius things about the business model was that it operated like a consultancy, but built contracts like a product company. That allowed them to charge based on the value provided rather than hours worked, then pull the best lessons from the deployment back into the main product.