This is an image of the decision tree that Slack used 5 years ago to determine whether to notify someone.

Every time you add a customization option like "don't notify me during these times in my time zone" or "mute notifications in this thread" etc, you add another branch or set of branches to a decision tree.

This is NOT a bad thing, but it is a reason that I am resistant to customization. Each knob you add expands software complexity and room for bugs.

Source: https://slack.engineering/reducing-slacks-memory-footprint/