I'd find it handy. I think there's some risk in agents tripping over stale tickets and consuming tokens - I see it with .md all the time.
Tickets by dependency would be nice (although my agent hasn't really used dependencies yet), and ideally something to just quickly wipe out closed tickets with a single command would be nice.
Digging the idea and incredibly simple implementation - but do you have a model in mind for clean-up? I've been working with it for an hour and have ~30+ tickets across a series of tasks, which are all just named by ID so no obvious way to purge (I could be missing something obvious).
Also, no concept of tags/labels? Are dependencies your primary means of organization?
Hope you enjoy - I've been on it for a few years after bouncing around a variety of tools and I really have no major complaints. My main concern is risk of eventual bloat, but so far it hasn't been an issue. I feel like it does a good job of letting you pick and choose what you want to use, hiding the rest.
Side note: although TickTick supports notes, I don't use them. I dig UpNote, another not-super-well-known but simple, cross-platform, and inexpensive tool. It's basically the feature-set I wished Evernote stopped at (super subjective, maybe too simple for most here).
Just because they don't feel the price is right/competitive doesn't automatically write them off as not your target market/ICP - it could still be very valid feedback, especially when competitive options may be cheaper.
Personally I pay less than 1/2 the sub rate they're charging for TickTick Premium, and love it. That's not to say I wouldn't pay double for what it gains me (I definitely would), but given that TickTick is a viable option - I don't need to.
Tickets by dependency would be nice (although my agent hasn't really used dependencies yet), and ideally something to just quickly wipe out closed tickets with a single command would be nice.