Here's completely different point of view - I assume other tools / repo hosting solutions can offer same feature, but as developer, Jira issue and BitBucket repo commit linking makes it much easier for both code reviews or tracking down issues for previous changes. Game changer.
Can't say I'm fan of their new UI tho, seems slower, unpredictable and not as clean visually as the last version.
As for "agile"...
The second Jira/agile is ONLY used to wrangle in and deal with those pesky developers, and doesn't get buy-in from rest of the company, you might as well give up there and then.
That's not to say if directors of company / project can only deal with waterfall approach that you can't make "waterfall-ly sprints" work for both directors and developers.
True waterfall, waterfall-ly and true agile all bring something different to the table, saying there's only one true workflow (or language, or framework, or infrastructure setup, or ...) in my humble opinion seems extremely short sighted.
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