The people who haven't paid their rent have done so by and large because they couldn't afford it, not because they just chose not to. Paying off their rent helps those people, the people who couldn't afford to pay it themselves, and ensures they don't lose their housing as a result.
It certainly is true that landlords benefit from this package as they get their money, as opposed to an alternative like forcing all rent debts to be forgiven. But "landlords benefit" isn't a harm.
Perhaps a more equitable solution would have been to determine the median rent across the state and then give that amount of money to all renters. But that has a lot of difficulties, such as how do you handle folks who rented only for part of this time (including those who had to stop renting due to job loss). And what about folks who own their homes and are dealing with mortgages; paying off rent is likely to be more accepted by non-renters than a plan where non-renters get money and renters don't. Of course, the plan could be extended to people with mortgages too. Or heck, just give this money to every person over 18 (or 21?) in the state. This would presumably significantly expand the costs involved in the plan though, but it would certainly be the most equitable.