QR Codes is the main case I've looked at where the shorter link makes a difference in the complexity (and therefore scannability) of the generated code.

But otherwise I think it's about traffic and tracking.

First in that you can track visitors to the short link, perhaps in a more centralized place if your org has multiple systems or if you're linking to sites you don't otherwise control. And secondly it's used when tacking on tons of query parameters that would otherwise make it too long even with expanded character limits. And just aesthetically a short link might be more aesthetic in your post.

Imagine seeing "link.short/abcd1234" vs "linksrus.corporate/blog/2025/08/12/the-title-of-our-post.html?utm=something&some-other-tracking-param=abcdefghijklmnopqrstuvwxyz&even-more-data-in-the-url&some-hashed-value=QXNoIG5hemcgZHVyYmF0dWzDu2ssCiAgIGFzaCBuYXpnIGdpbWJhdHVsLApBc2ggbmF6ZyB0aHJha2F0dWzDu2sKICAgYWdoIGJ1cnp1bS1pc2hpIGtyaW1wYXR1bAoKT25lIHJpbmcgdG8gcnVsZSB0aGVtIGFsbCwKICAgb25lIHJpbmcgdG8gZmluZCB0aGVtLApPbmUgcmluZyB0byBicmluZyB0aGVtIGFsbAogICBhbmQgaW4gdGhlIGRhcmtuZXNzIGJpbmQgdGhlbS4KCg"