The first place was pre-jira popularity and we maintained our own system, or used systems from our clients.
The second place was a game studio and had many more bugs than any other place I've worked. One game title we had, we had around 29k tickets, and cleared out 7k in our biggest week. The speed of the UI actually impacted the effectiveness of our throughput at one point. We started with Traq, then hansoft. But I think jira won out over hansoft due to the ability to customize it and then sony just maintaining a jira for us that their teams used to coordinate with us, so kinda a no brainer.
The last one is interesting as Amazon has many tracking systems, and even if you use jira, over time the jiras were so crowded they had several, we used jira-4 (out of 7 or 8) before I setup one for our org. At twitch we've been consistent on our use of one jira instance since i've been there, but we've changed the url I think 4 times since during my tenure.
In all of these places we've had many codebases that outlasted the urls. All of those places I've been we just use the short numbers like AND-3421.
In the cases I needed to click them I could just use alfred or a tampermonkey script. It's a lot shorter as well.