But it's not quite clear unfortunately how much protection they actually offer. A bad player could still try to enforce some hidden EULA small print that claims to empower them to ignore the cancellation and send bills the old fashioned way after cancellation on the intermediary. I really don't know if Apple or Google are taking effective steps against schemes like that or if they have just been lucky so far that those scammers are still finding enough prey outside of the walled gardens.

(ps: re-reading this comment I find myself sounding more critical than intended, actually I love subscribing through that kind of intermediary, I'd even consider paying extra. I'm just afraid that the protection offered might not be quite as strong as it seems)