In your description, you used the word 'enforcer' for the entity that does the important bit. That entity isn't the contract.
Yes, the enforcer is not (necessarily) part of the contract. But if the right incentive system is in place and there is consensus that physical enforcement should happen - anyone approved could take that job/risk and be the enforcer.
With such a system you may not even need a physical enforcer since the risk of not getting the tenant out could be tradeable (like an insurance) and the owner would get his rent even if the tenant cannot be evicted immediately. In case of the tenant, there would be huge negative financial incentives to stay.
1. An incentive to evict someone. Money. Someone needs to get paid to actually do the eviction because they are taking on some risk - physical in this case. It doesn't matter how they get paid. A smart contract can do that.
2. "Social/Legal consensus" that performing the physical eviction is the right thing to do. The person performing the eviction should not get punished for it. If the state and breach of contract is transparent on the blockchain this consensus could be achieved.
3. A way to confirm the eviction to pay the evictor.
Also, you are ignoring the fact that, at least where I live, only one entity can legally evict a tenant - the county sheriff (in their role as an agent of the court). You cant just hire some random thugs.
Welcome to mafia shakedowns
> "Social/Legal consensus" that performing the physical eviction is the right thing to do.
That "social/legal consensus" is called laws, and they are enforced through a central authority.
> If the state and breach of contract is transparent on the blockchain
Who exactly is deciding "the state and breach of contract"? You can start from the fact that smart contracts are not even written in a human language.
> A way to confirm the eviction to pay the evictor.
People were paying each other for thousands of years without smart contracts
The same principle applies here as physical eviction is fundamentally about risk. There is an "auction" on the eviction and potential evictors can decide how risky the eviction is. More risky evictions will require a larger payout.