Obstruction-free is the weakest requirement, so your use of "even stronger" confuses me. In any case, in practice wait-free has this property a bit: getting th

Obstruction-free is the weakest requirement, so your use of "even stronger" confuses me. In any case, in practice wait-free has this property a bit: getting the guarantee of all threads making progress in finite time generally requires in them executing slower individually, on average, e.g. one common strategy is for thread A help thread B finish its work, because thread A needs that result.