Why is the landlord getting their counterparty financial information in a negotiation at all? The landlord is often a rapacious counterparty trying to negotiate the best deal that they can, and they have iron control over many state legislatures. You, as a tenant, have no ability to view their proprietary information like vacancy rate and rents. Yet they are able to give the prospective tenant a financial proctosigmoidoscopy? That's not fair.
The landlord lobby is well organized and well financed, and includes the following:
National Multi Housing Council
National Apartment Association
Builders Owners and Managers Association International
Institute of Real Estate Management
National Association of Industrial and Office Properties
National Association of Real Estate Investment Trusts
National Association of Realtors
National Leased Housing Association
The Real Estate Roundtable
The U.S. Chamber of Commerce
This does not include the highly organized and well-financed local and regional lobbies, who exert yet more control over state legislatures.
Being required to give the landlord your financial information should be banned. Credit rating is probably the best way to find out if a tenant will likely pay. Income should be off limits - unless maybe if the state requires the landlord provide a legally binding fact sheet about their finances and vacancy rates and actual rents, to level the playing field. And of course, bank accounts and employer login details should be completely illegal to demand.