My opinion is that the province ought to fund a large portion of municipal transit operations; given the post-COVID number of $4 billion or in subsidy so across the province, I think 1/3 of the subsidy (up from about 10% today with the gas tax fund) is reasonable, at about $1.5 billion annually. Though you'd have to juggle other use cases (healthcare, education). To prevent municipalities taking advantage of this for short-sighted (ahem, York Region, Ottawa) tax cuts, the province could set a limit at which point their subsidy disappears, eg. service must be at least 100% of 2019 levels, going to 120% (still leaving cities with a 20% drop in taxes, if they choose) in the future. There is precedent: the province funded 50% of transit operations until Mike Harris happened.
Wasaga beachgoers is probably closer to intercity transit; the province could theoretically fund an intercity bus service as well, running a parallel "Intercity" service (with the aim of profit) and "Regional" service (a baseline service for rural residents to access the nearest big town). But that's probably yet another conversation past the one above ...