Also perhaps there should be a new field for startups (yes i'm aware of 'proptech' but there has to be more than that), that will collect dirt on tenants to threaten them with legal consequences unless they pay.
1) Because screw you, that's horrible and you shouldn't do it.
2) Because all these digital key systems are horrendously insecure and much more open to thieves and crackers than than a plain old door key anyway.
(2) is negated very simply - have both old door key AND digital security key which auto closes if there are unpaid bills for say more than 5 business days.
Cyberpunk: Edgerunners has an excellent scene where something like this happens to a kid down on his luck.