The risk-free floor is around 4% these days. Because the return on any other use of capital must be risk-adjusted, the breakeven might be 6-7%. That is roughly a 3x higher rate of return than you needed to breakeven when the risk-free rate was ~0%.

Small absolute changes in risk-free interest rates cause many things to become unprofitable when the relative change in interest rates is large. A risk-free rate of 1.0% and 1.5% are both small but the latter is 50% higher than the former.