#deltachat is geared towards private group chats. In small groups technical moderation is not so important. A subset of people can always create another chat simply and continue there. Technical admins can only help so much. Maybe it's even the admin that is the problem?

There are >100 people chats e.g. from #38c3 or #fossdem25 that work quite fine. But YMMV

If you want Telegram-style channels with public subscription, then yes, some administration is needed.