Slavery would be a matter of contract law in the present day if it was permitted -- since people would be allowed to sign themselves into slavery in return for whatever they could get out of it.

You're not "allowed" to sign yourself into slavery, even if you want to (because the state won't enforce the contract).

Non-competes will have the same properties above (if this bill is passed), therefore I suggest that slavery is a valid analogy for non-compete agreement in this context.

This opens up the opportunity for further discussion. For example it can be argued that the state is defending your freedoms by refusing to enforce a slavery contract. On the other hand, it can be argued that the state is denying you the freedom to sell yourself into slavery.

It is interesting to consider the case of non-compete agreements in a similar fashion.

(Please don't be rude or I'll be uninterested in discussing with you further, and don't tell me what I get "points" for: I'm not in a competition with you.)

I agree with you that "slavery" was a sloppy argument, but indentured servitude is a better one.