Best URL shortener for each platform?

Kabo:

Relying on remote server opens up more possibility for tracking and makes me dependent on some server beeing online.

Then it sounds like you want a bookmark manager rather than a URL shortener. A “URL shortener,” to me at least, means you can generate a short URL that anyone can use to get to the original site; no different from sharing the real URL, aside from being shorter and requesting an extra server. https://tnyr.me/#3mMdjT8raY for example.