There's a distinction between doing something with people vs in front of people.

If everyone is also participating in experimenting, then it's easy and fun.

Everyone is taking a risk, sticking their neck out, together.

If you do something embarrassing in front of the group, it's ok, the other people did, too!

This can build trust and non-transactional relationships

If you're doing it in front of people, it's terrifying!

It only takes one participant not being into it to ruin the whole vibe of an improv session.

That collapses it instantly from a something with to being in front of.

Midjourney succeeded in getting people to experiment and play in front of others.