Sub-tasks -- community has waited 20 years for this critical feature

[pm64]

Please refer to Bugzilla issue #194863, opened 20 years ago, regarding "Subtask nesting and event triggers (hierarchical to-do)":

https://bugzilla.mozilla.org/show_bug.cgi?id=194863

The case for this feature was strong in 2003. Now, in 2022, issue #194863 represents a gap in functionality that is simply unacceptable. Sub-tasks are a standard feature of every modern task scheduling system, including Google Calendar, Todoist, and a plethora of others -- making Thunderbird's tasks interface (and by extension, Lightning as a whole) inadequate for many use cases.

I raise the issue here because there's obviously no plan to fill this gap in Thunderbird. Might Betterbird come to the rescue?