This creates a little need for trust among legal peers because this sort of thing can happen if one is not careful, but in a professional environment adding in things randomly is a serious breach of trust.
And I wouldn’t call it trickery, because that implies intent. I think the forces at play make no distinction between a knowing operator and somebody who just does what’s normal, what’s safe. I think plenty of companies slap an unintelligible ToS on their website not as a trick, not even thinking of it as unintelligible, but just because there’s good evidence that this particular boilerplate protects them in court.
Because if a new legal vocabulary was introduced, I would now have to read contracts in both "old legalese" and "new legalese".
I don't think it really matters how clearly contracts are written or how simple the language is; most people won't read them anyway.