EdJiang, please note this isn't to you directly (either as a poster or Uber employee), my engineer-brain is sort of thinking of loopholes and unintended consequences. I'm not expressing an opinion here.
How many "real" working hours does it take to get 25 working hours? I only found one reference (Berkeley Law) that estimated 1/3 of the time is downtime, so very roughly 40 hours a week? Of course depends on location, chosen time of work, and much more.
More cynically, would these companies be able to distribute work such that rides are given to drivers with more "buffer" before hitting these ACA payouts?
Again, not at Uber, Lyft and others specifically but the USA is a country where if we mandate workers with 30 hours get healthcare, employers may try to schedule for 29. I think it's unfortunate, but that's the incentive.
(opinion mode on: we need to fix healthcare as a country; the current state of affairs and likely the state after the Supreme Court hears Texas v. California in three weeks is ridiculous)