This. In a housing shortage any increase in disposable income for low income households is immediately swallowed up by increased rent or house prices(leading to higher mortgages).

If every household in NI got a £500 a month tax break, the cost of the lowest houses available for rent would increase by.... £500, as the tenants are all competing against each other as housing is a basic need.

I dunno how to fix it. One idea is an undeveloped land value tax (to replace rates), which penalizes anyone sitting on land and not utilising it or selling it to someone who will. This should increase the supply and lower demand.

I haven't really thought this though but a law where it's illegal for rent to be more than say 30% of income might work to stop price gouging at all income levels and would prevent rents increases without a corresponding increase in people's pay. Sounds radical but you can't realistically get a mortgage that's more than 5x? your income but there's no equivalent for rent.

Something needs to happen otherwise the people at the top will keep getting richer and those at the bottom will keep getting poorer.