I remember blackberry using bitly links in their developer emails in 2013, and at the time it was possible to see the stats of any link by just adding “+” at the end of the link (now requires authentication or maybe only paid users can lock that page)
It was dismaying to see that it got only 50 clicks or so lol
They’re useful for printed media
“Find more info at bitly/event” instead of “find more info at facebook.com/unnecessarilylongurlthatnobodyisgoingtotype”
Or for a qr code where it needs to be small and somehow your URL is too long
But yes, relying on a third party company for something that needs to last a long time isn’t really smart. There are many books that have online content now inaccessible because they used a link shortener that’s dead or that doesn’t let you update the redirection without paying a ransom (need to pay $120/year to bitly if you need to change the redirection)