No it's not easy to switch. Engineeting Organisations have invested a lot in the Jira eco system, that includes custom workflows that are understood only by a few to be able to alter them, users are productive right now with jira and nobody wants them less productive even just for a while learning another task manager. Here again the integration effort to migrate would scare any leader who would be blame for the impact on so many teams deliverables. The effort is enormous and error prone to take all the data in there, move it elsewhere, rebuild the workflow and integration configuration, while keeping track of lack of feature parity to write down an explanation before everyone complains and pre empting their request to at least provide a work around what they used to be able to do with 3 clicks. Confluence slips right in because it integrates very well with jira. Just embed a confluence page into a task, and just mention a jira task within a confluence page and you get a seamless experience. Yes we could use another wiki , and a good one as confluence is a calamity. But convenience is what organisations are after. Perfect is the enemy of the good they will say. I don't have a love for atlassian products, but they tend to do their job very well compared to the majority of the competition. You will always find one product that compares, or even is superior but overall, their product works. So here we are.
If they get plagued by further security vulnerabilities then companies handling sensitive data will concede to migrate, but it won't be simple by any means.
If you believe changing people's habits is easier than ever, it's rather the opposite. Workers are less and less inclined to learn any other way . The alternative has to be order of magnitude better than what they are using, otherwise they will resist the change. The fact is atlassian provide good to great products overall.