Scientific journals should not rely on ephemeral data on the internet. It doesn't even matter how long the url is.

Just buy any scientific book and try to navigate to it's own errata they link in the book. It's always dead.

Sure, just turn the three page article into a 500 page one with all the data and code.

Take a photo on your phone, OS recognises the link in the image, makes it clickable, done. Or, use a QR code instead

This is the answer; turns out that non-transformed links are the most generic data format, without any "compression" - QR codes or a third-party-intermediary - needed.