Responsible diversification

...or simply put: how to have a cross-functional team without risking Sprint goal failure

The issue

On one hand, Scrum is all for having cross-functional and self-managing teams vs. narrow-specialists, while on the other hand each team member should be able to finish every goal and task within a Sprint no matter how complex it is; this appears to be the most common Scrum paradox and I'm seeing numerous articles and even entire books on how to solve it

We want to:
   a) Make Scrum teams fully self-managing
   b) Have employees of all qualifications, both Jr. and Sr. to focus on the same critical company goals

We don't want to:
   a) Isolate employees by making them run sprints on their own just because they cannot yet work on all tasks in the team
   b) Introduce valid excuses as to why Sprint goals weren't met
   c) Loosen up the Definition of Done and affect team deliverable quantity and/or quality

Solution

Our goal is to always KISS so to fix the mentioned paradox we'll introduce some flexibility by allowing Scrum teams to be collectively qualified to achieve all assigned goals; what does it mean for Scrum teams compared to the practice so far:
   1) Each team member is no longer needed to be able to perform all tasks in the sprint
   2) Each team must still be able to complete all team tasks with sufficient quality
   3) Tasks achievable by select team members only are to be treated as high risk tasks meaning they must be marked as such and must be prioritized within the sprint
   4) Each team must make an Internal redundancy plan for tasks achievable by select team members only and lay out the redundancy pairs in Sprint planning meeting

In practice - teams

   A) Support team can have one part of the team (Writers/Analysts) focus on writing, analysis and other high level tasks first while Product support guys focus on handling the actual customer support and lower level writing, posting tasks

   B) Core developer teams can directly integrate Jr. developers, have Sr. devs focus on new development design and complex bug fixes while Jr. devs work on low/medium complexity bugs and following specs

In practice - individuals

   A) Working exclusively on simpler tasks or taking ad-hoc tasks and insisting there is no more work in the sprint left for you when all low level tasks are done is an excellent way to not advance your career and eventually have your regular review result in DNE

   B) If you can work on all team tasks, you must still roll up your sleeves when there is critical low level / transactional work left; taking lower priority but more complex work in such cases is even worse than not working at all