Well this conversation seems to pretty much explains everything.If there is a loophole, a union rep at ATU 113 will find it. Even operators who are fired sometimes get rehired
As incentives drive behaviour and the main TTC union has roughly zero incentive to respond to customer feedback or increase satisfaction.
And there's no feasible way for the union to ever be punished, even if they are the direct cause for decreasing satisfaction. At least not in the Toronto/Ontario/Canadian political/legal system.
So the result is unsurprising.
It probably will never be so bad that investing billions into the TTC will result in less than nothing, which happened in the most extreme cases of systemic problems, but it certainly seems likely that the return could be negative. i.e. a billion invested could only yield hundreds of millions in value to the city.