Yes, and it really helps communication to add to the previous idea rather than tearing it down.
Yes, and you can use it to bring new ideas into the conversation, without implying that the previous ones weren't good.
Yes, and it makes everyone feel really nice because their ideas are being valued.
Yes, and it's all about building up a conversation.
Yes, and you get the point.
Now under normal circumstances this is really lovely, although it's obviously not something you can actively sustain for much longer than a five-minute improv skit.
It has, unfortunately, become tangentially relevant to political discourse recently. Namely, this practice of yes-but-ing to other people's protests/political movements/slogans/petitions/etc.
For example, "Black lives matter." was responded to with "All lives matter."
"Women need to feel safe" was responded to with "Not all men are terrible people."
And this isn't really a "Yes, and" It's really more of a "Yes, but." And if you ever took an improv class, you will know that 'Yes, but' is not the same things at all.
'Yes, but' is actually just derailing the conversation. You're agreeing and then bringing up something new rather than adding something to the existing discussion.
When someone says "Black lives matter" say
"Yes, and we need to make sure that's reflected in our police force!"
not
"Yes, but white lives matter too!"
When someone mentions Cecil the lion's shooter being a jerk, say
"Yes, and it's insane that the laws would have allowed his hunting other lions!"
not
"Yes, but he's just a lion and really black lives are more important!"
When someone mentions gay "cures" and how damaging they are, say
"Yes, and they really should be made illegal!"
not
"Yes, but really climate change could kill us all!"
When someone says "Climate change is really scary.", say
"Yes, and there's a discussion going on about it internationally right now at (climate summit of choice)."
not
"Yes, but nuclear is really dangerous!"
In short, do not derail good, productive conversations about issues that matter by bringing up other things. Even if those other things are also discussions worth having. Because what that actually does is make people drop out of activism as a whole. It's draining to try to explain over and over why the issue you're talking about is important - It's absolutely impossible to keep trying to explain it when people are accusing you of caring about the wrong thing.
Those activists that fight to make the world better place to live in don't need their priorities sorted, even if they're fighting for something you don't think is that important. Fight for your issues to be heard- not to drown out everyone else's.