I want to agree with something you didn't quite spell out: the incentives are not really properly aligned in this kind of industry. You get paid up front, when people are at maximum motivation, but progress takes a long time and many people drop off along the way. Some kind of business model where you get a half-refund for non-usage would be a reasonable compromise for everyone, but I've never seen it in action.

Speaking for the people I know who are involved in this work, they are not cynical. They do this kind of work, instead of other work, since they genuinely want to help people. Our product worked if you stuck at it, so we spent a lot of time encourage people to come back each day and work at their goal. You can take my word about this, or not, as you like.

Something even a cynic would celebrate: there seems to be a push in some parts of the US health system to pay for outcomes (e.g. confirmed weight loss; stopping smoking) rather than processes (e.g. access to an app for losing weight; access to a quit smoking program). That's a really welcome development, it aligns everyone's incentives nicely.