Why we switched exclusively to GitHub Issues

Hell yeah.

The key to GitHub issues is that they are fast. I can make a ticket in seconds, which means I will make a ticket. Loading time is close to imperceptible on slow phone company DSL or slow phone company wireless.

Compare that to JIRA where making an issue involves looking at a few screens that look like the Space Shuttle cockpit controls, having to fill out a bunch of mandatory options that involve a huge cognitive load because they are incorrectly ontologized so that none of them really apply to the ticket you're putting in. Then you're waiting 20 seconds for pages to load even over a "business class" 50 Mbit/s connection.

Now maybe some of that is the fault of the customers and not Altassian because maybe they run it on premise and are running it on a ten year old "server"; yes, once in my life I saw somebody load a JIRA page in under two seconds. Similarly, it's the customer who added a bunch of screwy categories and made the manually. And it's not just JIRA, all the others ones are just as bad maybe worse.

I remember one product that made a big deal that it supported the agile thing and allegedly you could put an estimate in and then say you worked 4 hours on it, except that if you tried to do that it seemed anything would happen like maybe the estimate would be extended by 4 hours or the estimate would be set to 4 hours.

All of those features are "nice to have", but speed and simplicity is a "must have"