URL shorteners still serve a purpose for sms, marketing, smart redirects, and more. One of the ways to combat some of the concern around what happens if the service shutdowns is to use your own domain when creating short links. This allows you to export your links since you control the domain.
I've been running https://T.LY URL Shortener for the past 2 years and I'm the creator of the URL Shortener Extension (https://t.ly/extension) that has over 400K users. Let me know if any questions around url shorteners.