I agree it is more complicated than what I outlined above, but I do think the aggregate welfare lost from the detriment in service quality of car-hailing multiplied by the number of potential consumers hurt represents a bigger loss than any gain cab-drivers could obtain with this measure.
I find the measure exactly the wrong type of regulation, the one that hurts a large segment of society to protect a small group (which had already benefited from a decades-long state imposed monopoly and became stagnant and comformist as a result).
As a small disclaimer, I do admit I have a bias against cab-drivers in general, but I do not think it clouds my judgement in this case.