Palantir and Accenture are consulting company. They make money by reselling meat by the hours, as we say in business. They don't profit from what is created at the client. They profit more by buying cheaper meat (graduates) and reselling with higher margin to clients.
Google is a software company. It makes money on the software service they provide. They get the returns for everything you do. They get more money by you making "better" software infrastructure and services.
Palantir does indirectly profit from what's created at the client, by reselling the code created at one client to other clients later.
Consulting companies don't. The reason they are called in the first place is to make highly customized software.
Most consulting companies will pretend to re-use things across clients. In practise however, it cannot be achieved because it's going against their business model (yet they'll still pretend they do).
I'm not sure what you think the business model is that would go against code reuse across sites. If you can afford to negotiate for ownership of what you build at a client site, why wouldn't you reuse things that are common?
Like, the reuse thing isn't binary. There's a whole spectrum between 'give everyone exactly the same thing', and 'give ever y single client something built for them from scratch'. And if you can build something from scratch at one client site, take half of that to another client, take 3/4 of that to yet another, and eventually end up only having to build 2-3% of the thing at every place, that's building a product while already getting paid for it.
In general, strict consultancies are inherently unscalable and expensive, whereas SaaS has a unit cost of nearly $0. The benefits of consultingish, unscalable behaviors are known, in order to get to, and create new, scalable products.
Because there isn't much that is common. You're called to craft customised software, with special customization for the client needs and tight integration with the client systems.
Anyway, none of this matters. At the end of the day. A consulting shop doesn't bill software, it bills the hours*men.
Whatever spectrum you think you can achieve, your actual business model always push back to its extreme side.
I've worked at consulting shops trying to bill software as software. I've never seen it goes very well.