Why is there an assumption that all BTL landlords use profit to buy more ???
Ive written it once. £12 profit for a year of hassle and £~1700 paid in tax ! I won’t be using that to buy another place.
You also need rent to cover 145% of the interest if rates hit 5% with a lot of BTL mortgages. So you need significant capital up front.
It’s nots £12 profit if you have capital in the asset at the end. It’s £12 on top of the mortgage payments that you have made. And the few hours of work that you have to do will more than make up that.