Simple. Do you have the necessary personal correlation of power & power relationships, to hold onto it & secure benefical usage, against those who dispute you rights & or claims. It has not much changed, it's by & large still generally applicable today. Today there sometimes or quite often, a intervening third party a polity that asserts supermacy of it's established rules & in exchange of tribute/favours/taxes may intervene to protect title. 😊
He makes a mistatement: rent control statutes in reality establish principles of antitrust law- in that they prevent abuse of the market via price gouging. The harm to land owners is minimal outside restraining corporate profits to a reasonable standard.