You’re talking about Satoshi’s whitepaper? Because it talks about escrow services, etc. What principles are you talking about?

Bitcoin's trustlessness is not affected by people choosing to store their keys with a centralized entity; although the same can't be said about PoS coins. It's all about giving people the option to choose their preferred method of interacting with it, each with its own pros and cons.

> Trustlessness is all or noting, and once you trust someone you are just doing what we do now but far less efficiently.

Not true at all, as the GP explicitly mentions Shamir's secret sharing:

> Shamir's secret sharing (SSS) is an efficient secret sharing algorithm for distributing private information (the "secret") among a group so that the secret cannot be revealed unless a quorum of the group acts together to pool their knowledge. To achieve this, the secret is mathematically divided into parts (the "shares") from which the secret can be reassembled only when a sufficient number of shares are combined.

* https://en.wikipedia.org/wiki/Shamir%27s_secret_sharing

So you can trust various persons / entities such that m out of n need to come together before the secret is revealed. And each person doesn't need to have just one share out of n: if you trust one person more that you can give them two (or more) shares out of the n.