I think it more has to do with the necessity of the service versus the risk undertaken. I don't think anyone is suggesting that a grocery store worker is at less risk than a Tesla factory worker - the suggestion is that perhaps people need the grocery store more than they need a new Model 3.
My understanding is to assume the premise you are trying to prove in the act of proving it.
The one being accused of begging the question said construction is a necessary activity because society says it is necessary. But that doesn't mean it is necessary, which is what the law would seem to require.
Construction being more valuable for society than a Model 3 was part of the premise.
You took them to mean "Construction is more valuable for society -> Construction is more valuable for society" but that was not the claim.