This issue is such programs do not scale when transitioning to a higher economic class. The same programs end when they reach a threshold thus creating an economic loss for the individual. This leaves a gap to climb back up before actually rising again in net income. That gap can be very hard to overcome.
Yep, I've experienced the joy of getting pay rises only to realise I'd lost family assistance benefits, childcare rebates, etc.
Was sometimes left wondering if I was better off or not. It's the joys of a tier-based system. My family was very much blue collar, and have gone through the social mobility thing in a personal sense.
Overall, i'd say the following;
I'm passionate about access to good free education. To me this is the number one way in which we empower people to improve their own situation.
I want access to university to be based primarily on aptitude. Any payments should be deferable, and held at reasonable levels, with reasonable obviously being completely subjective.
I also think access to good health care, child minding, rental housing and aged care is vital.
Those are the basics of a healthy society, to me. We have varying success on those measures here in Australia, but any one of those lacking limits in very real ways social mobility.
In terms of specific welfare programs, it gets much trickier, in so far as I think there is invariably a level of measurement or assessment involved, and it's impossible to have a 'fair' set of measures. The best I've seen is to limit the gross unfairness.
So in overall terms, I agree, specific measures can be counterproductive at an individual level. But some of the things most important to social mobility are around access, rather than provision of direct funding to individuals.