Linear has offered free services to users impacted by Atlassian's outage through the end of the year. I took a look at it (we aren't impacted), and notice it can import tickets from Jira, and also has a "Jira Link" where you can use Linear as a kind of front-end to Jira if you aren't ready to go all in on Jira.
When we chose Jira, one of the points that was made was: If we decide to leave Jira, there will almost certainly be an importer from Jira to the new system. Which does seem to be true. We came to Jira from Fogbugz, and I spent the better part of a month writing tools to import our tickets and wikis. Jira had a Fogbugz importer, but it was horribly broken.
Looking at Linear, there is no such escape hatch, or indeed, searching the docs I saw no "export" or "backup" capability at all.
Thanks for the reply. Linear looks pretty slick, I'll probably give it a try with the Jira Link, and get some experience with it without having to do a whole conversion plus get buyin from the rest of the team. We weren't impacted by the Atlassian outage, but Linear does seem to have a pretty compelling feature-set.
Linear is phenomenal. Probably built for a different audience than Jira (it's like Superhuman for tickets), but if you want something that works well and is opinionated I highly highly recommend it.