I think the lines of optional get blurred when someone else can break your app and user experience.

At best, it can be a simple few lines code to filter or add support, at worst, it’s indistinguishable from existing content and there isn’t an easy way to gracefully ignore it - or people perceive it as censorship because they didn’t see it.

Decentralisation is a blessing and a curse. Is still prefer to have it than not.