Stepwise phaseouts often create more cliffs rather than avoiding cliffs. It is possible to do continuous phase out without cliffs (with or without bend points), the easiest way being to simply give a flat, income-insensitive benefit based on non-income qualifications, and then do the clawback through increases to marginal income tax rates, but if you are committed to clawback internal to the program you can do it through a fixed or tiered marginal clawback rate, instead of having a single or tiered set of benefit cliffs. But programs rarely do that, for a variety of reasons.