@hpaluchpe It’s all about the support and also the support process.
The Leap series is a snapshot in time from Tumbleweed. Maintainers by accepting a package submission agree to maintain for the lifetime (well as best they can), with critical bug fixes and CVE’s etc. But NOT version updates unless there is a specific reason…
In a lot of cases it’s easier from a maintenance point of view to submit patches or upstream updates to the rolling release than it is to backport parts to a release under maintenance and test etc.