Machine-readable contracts need to be much simpler and much clearer to work. I've suggested decision tables as a format; those are declarative, guaranteed to terminate, and have a simple chart form that's easy to understand. Yes, they're more limited.
It's not enough that contracts execute. They have to be amenable to audit.
There's this amazing lack of vision and inability to see that things can and will be innovated on. Why would it be anywhere near perfect by this iteration? Why would you expect that?
Also in terms of complexity - have you ever read an actual legal contract? Do you think 99.9% of people understand that?
Because e.g. computers despite being primitive were still very damn useful the very first time they were built. In fact their utility preceded their being built (e.g. to have them assist war efforts and research calculations), not vice versa.
Sounds like something utterly complex even to describe, so imagine how more difficult it is for any average person to identify as a problem they have and care about.