I don’t know where the figures quoted came from – I suspect a property that was bought some time ago.
For a recent buy, the interest payments + overheads would probably balance the income as things stand. With the new tax regime, the landlord will be making a loss.
[Ballpark thoughts, £200k property, interest payments £8k, rental income £12k, overheads & void periods probably £3k. So current profit, excluding tax, £1k. Future losses – considerable)
rents are already high, so it will be hard to put them up. Results – fewer landlords wanting to buy, therefore lower house prices